As is being reported at MotorCycleNews.com

"The new class will be exclusively for in-line four-cylinder four-stroke machines with the philosophy behind the new class being cheap, competitive and prototype racing to replace the current two-stroke 250 class.
...
Traction control will be banned and Dorna will operate a controlled ECU management system to keep costs down and also ensure a level playing field for participating teams and riders.
...
Ezpeleta wants lease costs for the new four-stroke class to be around less than 100,000 Euros."

Sounds interesting to me. I wonder why they are waiting until 2011. Having the new regulations in place by 2010 would be doable.

Hard to say what the racing will be like. A 650cc 4 stroke sounds like it will be much heavier than a 250cc bike. But then again the 800cc motogp bikes seem smaller than 600cc super stocks sometimes. So who knows what the bikes will look or ride like.