They had a good run, those Harmonix guys. After over 275 weeks, five years and more than 4000 songs, weekly Rock Band DLC releases are ending. According to Harmonix the staff are currently being reposition to work on other projects, so after April 2 there no more scheduled DLC releases. Whether there will be any random DLC in the future seems unlikely, though I'm sure Harmonix has some other music project up their sleeve to look forward to.
Aaron Trites, manager of community development over at Harmonix, provided the following statistics and final announcement:
"We’ve managed to maintain a consistent release schedule for a staggering 275 consecutive weeks, releasing over 4,000 songs for the Rock Band Platform, but in recent months we’ve scaled production down as we’ve transitioned resources onto other projects. With several new titles in development and developers needed to usher these new games along, April 2nd will be the last weekly DLC release for Rock Band."
From Rock Band to Rock Band 3, add in Green Day and Beatles titles, and don't forget a half dozen side-projects like Blitz and Lego. From Creedence Clearwater Revival's Fortunate Son in 2007 to the upcoming release of Kool and the Gang's Jungle Boogie, Harmonix has a lot to be proud of. Perhaps it's best if we don't consider this the end of an era, but the beginning of a new one.
Check out the full announcement from HMXhenry here.