I saw the movie on Friday (opening in the Bay Area).
I am a big fan of the book and the movie; although quite long is well done. The panorama and nature shots alone are worth seeing.
Many folks are very critical of Christopher McCandless and some don't like Mr Penn's politics but that aside it is a beautiful film that did the book justice.

It is funny that many criticize Chris for only taking a .22LR with him although many experts consider the .22 to be an optimal survival and foraging gun. Other than bears he probably could have survived with the .22 if he new a bit more about hunting.
After all according to his journal he killed a moose with a .22lr rifle.