Here (computerandvideogames.com) and here (pcgameworld.com) are interviews with the lead designer for the game. He talks about some of the new content (which will eventually be available for download via X-Box live, so fret not, X-boxers) and other aspects of the game.
Also, here (pc.ign.com) and here (gamespot.com) are some hands-on previews. They don't say much more than that the game will ship something this November. (I *know* I saw it say somewhere that the date was 11/18, but I can't find that now for the life of me...)
Rock Band Network DLC (Thursday; 160 pts) • Machinae Supremacy - Republic of Gamers Seven songs are leaving the Rock Band store on June 30: • Crooked X – Rock ‘n’ Roll Dream • Die Toten Hosen – Hier Kommt Alex (not compatible with RB3)