"The belief in the development community is that Microsoft will make Windows 8 a closed system, an operating system that seeks to more stringently control, much in the way that Apple does with Mac OS X and the iOS platform. This would allow Microsoft to better monitor the quality of applications running on its platform, but it will also wall off the most widely used operating system in the world from myriad developers. PC game makers use Windows because of the openness of the platform and its ubiquity. If Microsoft takes that openness away, what will developers do?"

Ref http://www.digitaltrends.com/computing/blizzard-agrees-with-...