I agree with you on Joaquin Rodriguez. He's been on the rise the last couple of years and I think it will be a big year for him. On another note, it'll be interesting to see if Van den Broeck can follow up/improve his performance from last year.
You also need to take a look at exactly how many teams are fielding a credible GC candidate:
Aqua e Sapone: Garzelli
LPR: Di Luca
So at least a third of the GC contenders are targeting the Tour (you think Gadret would prefer success in Italy or France?), several of them are over the hill and are realistically looking at stage wins (Garzellie and Simoni) and the rest are there because a) it's the Italian GT and b) they couldn't get a ride in the Tour.
I don't see Garzelli and Gadret as viable candidates either, but you never know - maybe this is the year Gadret starts to really come around. You've got to add Bruseghin and Pellizotti as well despite the fact they might not start as their teams' top option. I think Mick Rogers could also be a contender if he winds up racing, which I believe he's scheduled to do.
I agree with you that Lance will have a lot of say on how Astana gameplans the race, but I don't think he'll have near as large an effect on the other riders plans.
Anyway, it's still a bit early at this point. I think we'll have a larger list of GC contenders as things firm up a bit in the next few weeks.