Microsoft has not said when Vista's successor, code-named Vienna, might ship or what features it will contain. Despite the desire to make Windows releases more frequent, Ballmer said there will always be people trying to work on things that take years to make happen. "We just won't promise them to customers and hold up big releases," Ballmer said.
As an interesting tidbit, Ballmer said in the same speech that a miniature Sony, Yahoo and Google lived inside Microsoft, aspiring to come out. Sounds creepy.