It's the MS bane: whichever market it enters, an uncontrollable appetite for domination that makes it desire whatever, goods, power, user base or other, is owned by the leader it wants to dethrone.
So its appetite was aimed at Sony in the past and it's aimed at Nintendo now.
This attitude can work when MS aggressiveness, greed and rapacity may be deployed at their full strenght, but with Live, Zune, XBox 1, and now, it seems, XBox 360 too, it looks like it doesn't apply.
This attitude, also, in fields with volatile trends, makes MS chase the coolest of the moment and frantically change style whenever another competitor becomes the coolest.
Childish? Judge by yourselves. Facts are that MS didn't conquer a monopoly anymore after Windows and Office. Luckily.