Windows 8, Microsoft's bold new operating system, officially debuted this morning at a coming out party in New York City highlighted by a display of the wide variety of devices on which it can run - from PCs to tablets to hybrids to laptops to notebooks.

Microsoft made big bets on Windows 8, Windows Phone and Surface tablets in 2012, and now it needs to make those bets to pay off. As more consumers and businesses go mobile, 2013 will be Microsoft's most challenging year yet.

At the time of writing, Windows 8 could be the biggest thing Microsoft has done wrong -- ever. But it could also wind up being one of the best things it has ever done.

Microsoft's radical shift to touch-centric computing in Windows 8 is far from the only difference between the new operating system and its predecessor.