Contador has had a great season already. Yesterday and today he trained in the Pyrenees doing recon of Tour stages. It sounded like today he's done the hors categorie Port de Bales.
I agree with the OP's concern about the rest, though. Evans peaked too early in the season, which meant a surprise classics win, but he had to do way too much work at the Giro. He has to be spent, and even if he can recover for the Tour, I doubt he'll be able to prepare for it properly.
Sastre might be able to bounce back because he had something like eight months off. I don't know if he has more to give, or if he's on the decline like the Eurosport announcers seem to think.
Wiggins and the team have everyone convinced he just trained through this one, and he'll lose two kilos and be a TdF stud. I'm not convinced. I agree that Frank and Andy haven't shown any form at all, and I don't expect much. I've said since February that Armstrong won't be there, so I'll stick with that.
Liquigas could be in the mix. Basso was peaked perfectly this week, so I don't think he can do that again. Nibali doesn't want to be there, but the team is sending him to training camp anyway. Pellizotti is a wild card if he can sneak in. Then there's Menchov.
The good thing, and this is the only time I've called it that, is that there are 22 teams, and lots of possibilities. People could surprise, like Wiggins did last year. But there will be lots of entertainment anyway.