The Professional Developers Conference is the main conference that Microsoft holds every couple of years to let developers see where they are heading with their internal projects. It is very much a futures conference. PDC 2007 has just been announced. It will be October 2nd to 5th 2007 in Los Angeles. For more information, see:

http://msdn.microsoft.com/events/pdc/

There's also an RSS feed to keep you up to date.

Greg