Very few details known at the moment, it was announced via Josh Drescher's twitter and at present all we know is what he has said, so it could be just him, it could be more. No clue as of yet. However Josh has said a few things:
"Not EXACTLY how I expected the day to start: As of 11:00 AM today, I am no longer an employee of EA Mythic."
"FYI: I can't get into details (and, in fact, don't HAVE many more details), but it was a layoff. I wasn't fired and I still love Mythic. "
"Quick note, then I'm going offline for a while: WAR isn't dying. The game is better now than ever before and more goodness is on the way. "
Obviously despite Josh's assurance's otherwise, this is going to get the Prophets of Doom going into overdrive. I'll just say treat everything you read on forums and in region chat with a large pinch of salt.
As for Josh. Thanks for everything you've done with Mythic & WAR, it must have felt rather unappreciated at times. Good luck for the future old boy.