Spoiler alert: Kanye West will appear on the season premiere of "American Idol" Wednesday night. 

Oh wait -- you already knew that. Everyone already knows. In the closing minutes of the 15th season launch, a "surprise" guest turns up; guy is not bad. Think he should go to Hollywood.

This final season boost provided by Kanye has been a badly kept secret for months, but Fox did release the video late yesterday. He performs a bit of "Gold Digger," in a family-friendly, or at least beeped version.

What do we learn from this? A few things...

Foremost, he suggests a lost opportunity -- "Idol" has long eschewed hip hop, reasoning that it would disenfranchise older viewers, or those very viewers who have kept this franchise afloat in recent years as younger ones have left. Nevertheless, rap is mainstream, has been for decades, and yet...no presence here.

Second, Ryan Seacrest really does have some pull after all. His production company is overseer of the Kardashian empire, and so a quick call to its most famous family members yielded this nice little cameo, also a plug for fashion line Yeezy.... (And Kim also appears Wednesday night, briefly).

And... do check back a bit later for my 15th season launch review.