not really ..
the 360 has a lot of very good games and is sure to have enough support in the future, so I don't see why they need to "do sth. fast"
there is no need to stay above the PS3, but knowing MS they will push Natal, which might make the 360 outsell the PS3 again, but tbh MS already won, because they managed to make their system profitable and to satisfy their customers with their games line-up and services