Let's see: "Full of surprises."

Last show.

Legendary run.

Nothing left to lose (as if there ever was).

What exactly will the final edition of "Late Show with David Letterman" be when the cameras gleam hot and the host sprints cross-stage for the last time?

And that will be in just a few hours.

With Bill Murray's last appearance Tuesday night, the "surprise" possibilities would appear intriguing indeed.

[And for those just coming to this post, here are the celebrity sightings made by reporters from AMNew York, and by people in line at the Ed Sullivan Theater: Jim Carrey -- with  massive beard; Jerry Seinfeld; Chris Rock; Steve Martin; Barbara Walters ..

 And seen backstage: Tina Fey, Julia Louis-Dreyfus...

 Are they "surprises? Or "gawkers?"  Or "Top Ten'ers?" Maybe all three?].

 Some perspective. There are certainly any number of ways to think about last shows, but the best way to think of this one is to consider the man about to be celebrated. David Letterman is not someone who cherishes either surprises or celebrities. He does cherish history and those who have helped him to make that history over these years.

Moreover, he has only one real precedent to consider -- Johnny Carson's, on May 22, 1992. In a final installment without guests -- Robin Williams and Bette Midler took on the final guest role just the night before -- Carson instead spoke to family and friends in the audience seated before him. The end was wistful and melancholy: A sense of time and history passing on, in one final exhalation.

He spoke to his sons, Cory and Chris, and mentioned his other son, Richard, who had died not quite one year earlier.

Everyone in that audience knew they would never see Carson on TV again, and only rarely see him in public. With one or two brief exceptions -- one instance on "Late Show with David Letterman" -- they would be right.

No one has that sense of finality with Letterman. He will be back, colleagues believe, in some capacity, possibly radio, possibly the Internet, with Jerry Seinfeld's Crackle series believed to be one inspiration.

Wednesday night is "goodbye," not Bilbo Baggins disappearing into thin air ("Lord of the Rings" and Ian Holm fans know of whom and what I speak).

But how to wrap this?

Foremost, realize that "surprises" to us should also to some degree be a surprise to Letterman; he quite possibly doesn't know who will come by, or what will happen tonight.

Also consider that too many surprise guests tend to gum up the proceedings and, 'ere long, the farewell celebration turns into a cameo parade.

The obvious way to resolve that traffic jam is via a final "Top Ten," presented by 10 famous retirees. You can pick those names out of a hat right now: Jay Leno, Jon Stewart, Regis Philbin (who was on last night), Tom Brokaw, Jerry Seinfeld! (Final Top Ten: "What should Dave do in retirement?" Too obvious? Yeah, 'fraid so.)

But there will likely be guests, and while their appearance may be brief, they should be memorable. So to the list, and as usual, caveat emptor. Maybe no one from this list will be there. Maybe no one will turn up tonight! That would be a surprise, too.

Regis: Oops. Never mind. He was on Tuesday night. But no reason for a final curtain call?

Jay Leno: So much has been made of this that an appearance would almost not even qualify as a surprise. But there's something appealing -- in theory -- about this. The great loop of late night history finally closes -- the guy who took the show that Dave should have had in the first place comes to say goodbye. Ahhh. The feud! The bitterness ... Suddenly this doesn't sound so appealing after all, and instead freighted with baggage. But I honestly believe all those bygones have long been gone; Dave has always had enormous respect for Leno, vice versa. No reason a couple of old retirees can't sit down for a few minutes to talk about old times. But do you want Jay as the only guest? Not really -- for the same reason Dave didn't go to Jay's last show. It then becomes about something besides a "farewell" or celebration," but a "news story." [Update: "Late Show" EP Rob Burnett has been quoted saying that he doubts Leno will be on the finale; so this speculation may be a moot point].

Jerry Seinfeld: Yes, good idea. Certainly as part of a "Top Ten" coterie. Seinfeld has been a terrific guest over the years. No matter how many times he's been here, a last one would still be welcome.

 Billy Joel: Another longtime association, including the first "Late Show." Billy -- like Letterman -- is now officially a "meta" figure, above and beyond the fray of the grubby celebrity parade. He doesn't need to be here, but I think Letterman would love to have him here. A New York institution closing out another New York institution as musical guest. A winning combination. (And, by the way, EW is reporting that Foo Fighters is the lilkely music guest. So... can the final episode have two? We await and wonder... Foo Fighters makes perfect sense: Great band, and Letterman is a longtime fan).

Derek Jeter: From the sporting world, a perfectly perfect surprise. Another retiree, too. Possibly Joe Torre, as well. "Late Show's" New York ties -- deep and absolutely core to this long and happy run -- must be expressed in some elemental way tonight. Jeter would be one great way to do this; Joe, too. 

Jon Stewart: Again, as a brief walk-on, this would be a winner. Letterman graciously closed out Stewart's Fox show many years ago -- gracious because Stewart had been canceled, and one of the biggest stars on television helped him turn out the lights. There's some closure here, too.

Mary Tyler Moore: Absolutely a far-out wish-list name. I have no idea about her current health, and there have been rumors. But one of the greatest stars in TV, possibly -- arguably the greatest star in TV history -- bids farewell to Dave, even via satellite? Also consider that one of Letterman's first jobs many years ago was writing for MTM. She was a terrific "Late NIght" guest back in the day, too. Alas, this is probably a long shot.

Madonna: A can't lose surprise on a dozen levels, as long as Madonna doesn't break the bleep machine a dozen times over. There's history here, and Madge -- as much as any guest in Letterman history -- helped create his legend. Even if she is not here tonight, she should be here tonight.

Tom Brokaw: This is one of those guests -- or again, walk-ons -- that would be pleasing on a personal level for Letterman. They are friends -- actual friends, if you can believe that -- who have socialized (if you can believe that) outside the confines of television. They have those Montana spreads, but also -- I think -- share common ground about life, country, career, politics. Letterman is genuinely fond of Brokaw, and Brokaw of him. This would be a nice surprise.

Bruce Springsteen. Everything just noted about Joel -- exactly the same here. There's long history -- Bruce closed out "Late Night" -- and also that institutional glow, and a New York glow. Springsteen's career is longer than Letterman's ("Greetings from Asbury Park" -- 1973) but the lines pretty closely match up otherwise.  

Aretha Franklin: Queen of soul. A wonderful surprise. This would be a slam dunk.

Sir Paul McCartney: Back at the Sullivan? One more time? Until Colbert has him on? With Dave? How About Billy, Bruce, Aretha and Sir Paul. Singing together.

Mick Jagger: Come on. You asked for a wish list. You got one.

"Morty," Robert Morton: A little insidery perhaps, but Morty -- before his forced exit a decade ago -- had a more or less regular on-air presence. Fans certainly know him and remember the former exec producer. Morty -- I hear -- was at the Friar's club staff party recently so maybe all the old wounds have healed. I think this is a real long shot by the way.

Rudy Giuliani: I think this a real possibility. Letterman lauded him in the wake of 9/11, and Giuliani has hung around this run for many years. Sure, the mayor has done some interesting things in recent years -- possibly those don't square with Dave politically (you think?) -- but there is mutual respect nonetheless. Plus Rudy would bring back some more of that closure -- of years past, some good, and one day in particular, tragic. Consider here, I think, the possibility of Mayor Bloomberg as a walk-on, too.

Hillary Clinton: A long shot, but who knows. The problem is that this sort of appearance is then interpreted as a political appearance, or a campaign stop. Does Letterman or his staff really want to overshadow the final show with headlines that read: "Hillary Clinton surprise guest on final 'Letterman.'" It just seems ... unseemly. But there is a bit of history, too -- a long ago feud, and one resolved. A fun, or certainly surprising way, to defuse or poke fun at the political grandstanding of this would be as follows: Have Clinton and Sarah Palin, or Bill O'Reilly, read the final Top Ten list.

Dorothy Mengering: I save the greatest potential surprise until last. This could simply be an impossibility; she will turn 94 in July and I have no idea about her health, but one assumes travel to New York would be unlikely. Possibly via satellite? Not sure, but as a wonderful surprise for the guy retiring, you can't ask for a better one: Dave's Mom. Expect other members of the family to be in attendance -- he has two sisters -- and wife Regina and son, Harry Joseph.