I think this is timed mostly for stockholders. Sony needs a win, some hope on the horizon. They can't afford more and more quarterly earning to come out with discouraging news without something to get people talking about them again.
But I think it's bad for the PS3. It still seems to be selling relatively well, but this could affect those sales a lot.
As for MS, I think it's possible that the consoles will share a lot of new features, so not everything will seem all that original whenever they announce. I don't think that'll affect much, though, outside of arguments on forums. For the common consumer, things won't matter until they are about to release.
My personal opinion? Good for US, because this will hopefully put a lot of the stupid rumors about the PS4 to rest. Of course the NexBox ones will still persist ......
