The problem is, even at top form, he snot a match for Schleck and Contador without the toure being really kind to him - i.e. 2 long, pancake flat ITTs, and no MTF (and in fact no more than 1 cat1 climb a day in the Alps/Pyreneews). Evans just isn't a good enough climber to be able to stick with *every* move, in fact probably isn't, as a pure climber, one of the top 5 climbers in the GC hunt. The thing he does well at are early tour flat ITT. At the end of a 3 week tour, or over a more hilly course, he isn't even good enough in a TT to pull out any time on Contador/Menchov/Basso/Sanchez, and they are all more than capable of putting time onhim overall in the mountains if they ride it well.
Evans should focus on doing a couple of the Ardennes, then Giro, then take a break for the TDF to try and go and win the Vuelta. If he doesn't, and tries for too mucbh, I just can't see him ever winning a GT, which would be a shame (although amusing to tease certain posters with...)
Changing teams would also be an idea, as without a large amount of recruiting over the winrter, we've seen here and in Italy that his tema just aren't strgon enough in the mountains - especially when you'll have a strong Liquigas train in the Giro with the Italian teams also strong, and in the Vuelta Caisse having a stronger team. The problem is there just isn't really any teams who he could go to - Lotto actually may be ideal as they have a really nice lot of young climbers coming through, but I can#'t see him going back there