I don't know why exactly, but I have had a feeling for a while that Alan Branch will fall. It just reminds me a lot of the Vince Wilfork/Tommie Harris situation a few years ago. Everyone seemed so sure that Wilfork was going to go high, but both of them fell a little farther than they should have. I think Harris went around 13, and Wilfork slid all the way to the Pats in the 20s.
Something tells me that Branch and Okoye could end up doing the same sort of thing - where Okoye goes first right around #10 and Branch falls a little deeper into the draft.
As for the rest of Mel Kiper's board, I don't think you can fault any of the draft gurus too much. So much of the time all if takes is one big need or one team to fall completely in love with a player to throw everything off. All you can really do is hope they give you information and tell you who should be good and why.