I might be forced to eat my words, but though Cadel is a fair chance for a top ten, or even a top 5, he won't win it without a blow out from the other contenders. Both Schleck and Contador could take 5 min from him over the mountains (if they are in peak condition), and neither of them are the soft time trialists they used to be (Contador has actually become quite proficient). I've watched Cadel throughout his career, since he switched from mountain biking, and I can't say he's ever looked like winning a tour. I know he's come close, but even while finishing only 23 seconds behind, he never actually looked like he was actually able to take enough time to win.
All of that said, he's in with a chance, and I'd simply like to see Cadel on the podium. He needs to overcome quite a few people in order to get there, and (as well as Contador) he's taken valuable time on Vinokourov (31s), Van Den Broeck (38s), Roche (52s), Basso (56s), Hesjadal (1:13), Kreuziger (2:20), and Sanchez (2:35). Of those you can probably discount Vino, who simply can't climb well enough now, and possibly Roche and Hesjadal, who I don't really think are anything more than low top ten riders at the moment (willing to be proved wrong, but their results suggest they won't be winning any grand tours quite yet).
In the race for the podium, the time on Van Den Broeck, Basso and Sanchez will be extremely helpful. Sanchez came 4th last year, and was running third until Menchov produced a skull crushing final time trial, while Van Den Broeck came 5th. Basso bombed out completely, but he had already won the Giro, so that might have had something to do with it. All are good climbers, but Cadel can beat both Sanchez and Basso in a time trial - though Van Den Broeck has shown little sign of it recently, he is potentially the best time trialist of all the major contenders.
Of those he didn't get time on, I suspect he'll need to watch Gesink (12s behind) who's another younger climber, Wiggins (4s) who's really quite similar to Cadel in terms of style, though not quite as good a climber, and Tony Martin (5s) whom I still don't think can climb, but who has an almost Cancellara like ability in the TT. Radioshack will be there too, with both Horner and Kloden posting good results this year.
If he wants to podium, and assuming Andy and Alberto are in a two horse race, he'll also need to get over Schleck the elder, who is, at least on paper, almost as good a climber as his brother. If Frank is performing well he'll be able to out climb Cadel by a wide margin, but he's a poor time trialist, so Cadel has a chance to take back big time there.
Cadel has one final problem, and that is the prevalence of uphill accelerators in this year's tour. Contador, both Schlecks, and Gesink (and potentially Sanchez and Basso) can all accelerate up a hill, and continually change pace, in a type of mountain attack that Cadel has never been able to follow. Add to this his age and it will be very difficult for him to stay in contention over the worst sections of the HCs. That said, Van Den Broeck, Wiggins, Kloden, Leipheimer, Martin, and a host of others who don't mind climbing, but can't dance up a mountain, will be there, so he'll have company.