I'm as shocked as anyone that the Texans didn't pick Bush but at the same time Williams is a freak, 6'7", 295 lbs., and runs a 4.73! While I agree Bush is a rarity and definately a special player, keep in mind the last player to carry Williams similar make up was Reggie White. I myself wouldn't have passed on Bush but at the same time I know I would have given Williams a lot of thought.
Now here is how I think the rest of the top 4 picks will go down...
1. Texans- Mario Williams
2. Jets- Reggie Bush (trade #4 pick, #29, and a few others)
3. Titans- Vince Young
4. Saints- TE Vernon Davis or OL D'Brickashaw Ferguson
The Saints aren't going to want to move down to far in the draft because they want someone to add to the offense to help out Brees... You could argue that if SF was willing to deal their #6 and #22 picks in the first round they would have the best offer of any team to move into the #2 spot if New Orleans chose to trade it, but, you won't see that happen because the 49ers have way to many holes to fill and trading away another 1st round pick won't help with what they're trying to do... Although, I think they should.