Tighter integration into Photoshop, maybe even replacing Bridge. (you don't have to "export" from Bridge, but you have to do that from LR. From Bridge, you can get certain PS features for batch processing in PS, but from LR you can't do anything).
ABILITY TO READ LAYERED FILES, so I don't have to check the "maximum compatibility" checkbox in the Photoshop preferences, which blows up file size.