I don't have a dog in the 2012 MVP fight. I was fine with either guy winning. Both had outstanding seasons.
However, the assertion that Trout had one of the best seasons ever relies on WAR, and his WAR figure relies on us believing that he indeed was Superman in CF. He's actually having a better 2013 at the plate, but nobody's calling it one of the best ever because of his defensive stats.
For instance, let's say Trout's just a really good fielding CF (most CFs are). Then his 2012 was just a really good season and not some once in lifetime experience. Basically what I'm saying here is that it seems to me that the arguments for both Cabrera and Trout had their fair share of built-in hyperbole.