A source has told them that iTunes 9 is said to include Blu-ray support. Also, the update may finally include the ability to visually organize and arrange your iPhone and iPod touch applications.
Another feature that wasnt so clearly described to them was some kind of Twitter/Facebook/Last.fm integration. Perhaps the broadcasting of what song is playing to your friends?
BoyGeniusReport hypothesizes that the update may come in September around the same time that iPod's are usually refreshed.