Preview at WWDC likely in June, followed by September launch.
Microsoft's Steve Ballmer to Present During Apple's WWDC 2010 Keynote?
According to Trip Chowdhry, an analyst with tiny Global Equities Research, 7 minutes of Steve Jobs' keynote is allotted for Microsoft. Microsoft will reportedly be talking about their development tool Visual Studio 2010. The new version of Visual Studio will reportedly allow developers to write native applications for the iPhone, iPad and Mac OS.
The move would be a big surprise given Apple and Microsoft's competitive history. In addition, the announcement of PC-based development suite for iPhone and Mac OS would be major announcement. At present, developers may only create iPhone and Mac OS applications from within Apple's own Xcode development suite which only runs on Macs.