Well, my speculation (emphasis on speculation; I never said it was actual) earlier was off a little. Oops. Turns out the only Idols featured in People's Sexiest Man Alive issue were Chris Daughtry and Adam Lambert. David Cook and Kris Allen were featured in a video on the Sexiest Man Alive page but were not included in the issue.
Because I keep seeing this repeated everywhere, I would like to emphasize that there is no ranking for the Sexiest Men, outside of THE Sexiest Man Alive for this year, Johnny Depp. People's website put up a photo gallery up of some of the men in the issue, and some people got confused and thought that since the photos were numbered, they were ranked. That is not the case. There is no ranking outside of THE sexiest man alive for 2009, Johnny Depp (I beg to diffa, but that's another story. BRADLEY COOPER got screwed!).
Adam was listed under "Sexiest Rocker" with a small thumbnail-size photo (with the same picture and quote they used on the People website). Daughtry got a full page under "Sexiest Song" with the same photo from the website as well (also in this category are Flo Rida and Josh Groban).