Interesting development. It seems, as part of the iTunes extras, INTO DARKNESS has an enhanced commentary track, exclusive to iTunes. Get this; the enhanced commentary is the IMAX version of the film, i.e., footage shot with the IMAX cameras opens up to 1.78.
This is a seconded encoded file, as part of iTunes Extras. The first encoded file (the film itself) is in 2.39, with no commentary track. Even more interesting is that the BD will not have an IMAX version of the film on any of the releases.