Avatar and Digital Emily are the reasons why I'm so confident. Digital actors in Avatar are very impressive, and as a (former) CG nerd I do think that Avatar has crossed the valley -- or at least found the way across it -- I just don't think that this is proof enough for general audience and critics.
I think before the critics will be satisfied, one would have to make an entirely CGI film that wasn't Sci Fi, or fantastic in its setting or characters.
Something like a Western that had Clint Eastwood & Lee Van Cleef from their Sergio Leone Glory Days, alongside modern day Western Stars like Christian Bale, or.. That Australian Guy who was in 3:10 to Yuma. If we were to see CGI Movies, such as I mentioned, with the Avatar tech (or Digital Emily), then I am sure the critics and public would sit up and take notice (and immediately launch into how it was really not CGI at all, but really a conspiracy to hide immortality technology from the greater public).
I would like to propose this as a thread for people to write in their predictions for the next year and the next decade, when practical with probabilities attached. I'll probably make some in the comments.