Death of Microsoft? That would be the day. Even if a new operating system happened to overcome Microsoft's OS's, they have their hand in so many other things now I think it would be nearly impossible that they died.
Plus they obviously have the money and resources available to become the best at whatever market they dare to enter. If they really wanted to make Microsoft toaster ovens they would probably end up coming out with a top seller
As for needing a new operating system, probably not. Like almost everything else in this world it seems it's all about 80% profit, 20% innovation.