Saw this over on Trekmovie:
"TrekMovie has been told the release will include brand new special features including an audio commentary and documentary. CBS is not officially confirming details yet for either S3 of TNG or the new "Best of Both Worlds" set, but both are expected to be released on the same day."
Not sure if that means the commentary will ONLY be on this separate release or if the commentary will be split up between season 3 and 4 for the season sets? Looks like it will also have other special features as well. Although again I wonder if they are exclusive or will be split up between season 3 and 4? I would think BOBW would be getting special features on the season sets as well since it was such a pivotal 2 part episode.