I think Windows 8 will be fine for a user interface on a console, which an entirely different beast than a PC operating system. But I think that does suggest they’re mostly worried about catering to their entertainment means and not AS much about games (which is also suggested by the recent interviews with one of Xbox’s founders a bit ago when he expressed disappointment in their lack of focus on games). And a “Red Ring” situation seems highly unlikely. That was their most massive failure in the Xbox brand’s history.
I highly doubt that Microsoft will pull anything in that they don’t have already. Sony’s network of first parties is just so good, and we don’t even know what most of them are working on. I just don’t see Microsoft coming close to beating Sony in games. Especially as things move more and more digital, with Sony’s amazing PSN exclusive titles, PS Plus, and their new Gaikai-based services. GDC and E3 are going to be very interesting.
What they needed to do is establish themselves as the console for gaming, and they did that in spades today. Microsoft is concerned with the Xbox being the entertainment center of the living room, and Sony pursuing that perception would have been a massive disaster. They’re playing their cards just right.