Tbh, the main obstacle in fair evaluation of Michele's real chances in the Tour is that many things are still unknown. For the last three years his optimal racing program appears to be: Tirreno - Giro - Lombardia, and when he broke that program entering Vuelta 2011 he failed.
He is always good on the short climbs (regardless of the competition), on Giro climbs with Giro's competition (regardless of the climb, though there may be different points of view on what suits him more: 20km-5% or 10km-10%); his time trialing is pretty good if there are some hills along the route or the time trial is not long, and he is the one who never gives up.
But on the other hand:
- Giro 2011 showed that he is not a contender to Contador;
- There is very little information about Scarponi's true level outside his comfort area. Only this year's Catalunya and Vuelta i guess. Vallnord mtf showed that he can be good on the Tour-like climbs but Contador is a different level (again), in the case of Vuelta he just failed right from La Covatilla (stage 9). The only Tour-like time trial he rode over the last three years was Salamanca stage 10 in Vuelta 2011, it was a total failure but in Michele's defence the things gone wrong a day before that stage so i think he might do better there.
I think it's not enough to evaluate Scarponi in the case of the Tour, but unfortunately there is a lot of examples of riders that could succeed in Giro but fail in the Tour (due to differences in the field, course, pressure...), so basically the most of people expect Scarponi to fail in the Tour, while the others (the fans like me) expect him to do very well (top-6, top-5 or even the podium). The truth is probably somewhere in the middle, you never know.
As a fan of Michele I believe he can do well in the Tour, I can't be sure of course, but if he wants to succeed in France he should be ready to sacrifice his season. The problem is that I wouldn't like him to sacrifice his season just for one race, no matter what a race it is.