Microsoft (MSFT) CEO Steve Ballmer will retire within 12 months, according to a memo he sent to employees. To Ballmer's credit, Microsoft ranks among the world's Top 100 Cloud Services Providers, according to Talkin' Cloud's research. But the mobile world -- touch, tablets and smartphones -- were Ballmer's undoing. Read all the ongoing coverage about Ballmer's exit and Microsoft's next potential CEO on our sister site: The VAR Guy.