Steve Ballmer, the sweaty chief executive for Microsoft, may surprise us by playing a part in Apple’s keynote presentation at this year’s annual Worldwide Developers Conference. This, of course, is still all a rumor. But Trip Chowdhry, an analyst with Global Equities Research, insists that seven minutes of the June 7 keynote by Apple CEO Steve Jobs has been blocked off for rival Microsoft’s presentation on Visual Studio 2010. Chowdhry has reportedly stated that he believes Microsoft’s CEO Steve Ballmer could give the presentation. And given his love for developers, it could be quite…