Windows becoming less profitable
Well, they struggled to give 10 away.
Their massive failure to attract devs to their phone platform was a good reminder to focus on keeping the platform relevant to users (via default shipping with hardware) and devs (via strong toolsets). They've done surprisingly well in the cloud (given earlier competitive landscape) so while the tentacles are still reaching well into IT use cases of all kinds they have less reason to worry, particularly as client platforms become less critical in the Web app age and non-Windows related Azure revenues are heading in the right direction.