Came across this blog that, for people like me trying to figure out store exclusives... particularly what's on the Target bonus disc vs. the Best Buy bonus material.... gives a run down of the different featurettes from each store. They also do a review/explination of the "on itunes only" audio commentary.
I think I'm going with the Target exclusive namely because I...er.... saw the BB stuff online elsewhere (but damn, I have to say I hate the store exclusive stuff in general just because I like special features, but I don't want to have to feel compelled to buy 3-4 copies of a movie just to see all the special features available. What happened to the simple days, huh?)
TrekCore: Into Darkness Exclusives, Part I: Video VAM
TrekCore: Into Darkness Exclusives, Part II: iTunes Extras Enhanced Commentary