Harmonix has already promised an announcement next month at E3 (another Dance Central, easily the most well received Kinect launch title, seems likely), but Rigopulos threw cold water on speculation we'd be seeing Rock Band 4.
"We’re not planning a Rock Band 4 disc release in 2011," he said. "Rock Band 3 is a big game with lots of available music content and lots of new goals and challenges. We want to give our fans the time to explore that fully. But rest assured that Harmonix is still developing new ideas and concepts to advance the Rock Band franchise, and we look forward to sharing those when the time is right."
There's wiggle room there, of course, by specifically saying "disc release." Harmonix could implement new features into Rock Band 3 through a significant patch, but by all accounts, folks are happy keyboard tappin' on Rock Band 3. Having recently reduced the price to $19.99, there's now a very small barrier to entry.