OK, you heard it here first: Contador 1st, Sastre 2nd, and Menchov 3rd.
Contador has been very quiet so far this year, saving everything for July. He also has a super strong team to support him, provided they are supporting him. As long as Lance and Levi place nice and put there individual ambitions aside, nobody important should get up the road. Sastre showed great form right at the end of the Giro. The Cervelo team is strong but lacks the big-gun climbers. Menchov will definately rock the time trials and maybe a hilly stage, but my hunch is he burnt too many matches in May.
Other predictions:
More dopers will get caught, big names just like years past.
Lance may be allowed a stage win (Ventoux i'm guessing), but for the most part, he'll be Alberto's bitch for 3 weeks. Neither one will win if they make this a repeat of the LeMond/Hinault spectacle from years ago. More recently, the infighting between Vino, Kloden, and Ulrich at T-Mobile. Speaking of Vino, interesting to hear what he is saying about already being back on Astana. I wonder what pull he really does have with the Kazakhstan supported team. Could get VERY UGLY.