From Joystiq:

Aside from announcing the first three Beatles albums to be released as DLC for upcoming tear-jerker The Beatles: Rock Band, MTV Games and Harmonix today revealed intentions to bring the Rock Band DLC count to 1,000 songs by this holiday. At the current rate Harmonix is releasing songs for the franchise — without factoring in the Rock Band Network — that’s roughly 500 songs per year.

My wallet gently weeps.