I wonder if Mary Jo got this a little bit wrong. I was in the Monad breakout session at TechEd 2005 yesterday, MGT320 Next Generation Command Line Scripting: Monad by Jeffrey Snover. The room was packed out, with many more, like me, sitting on the floor. It was a big room, so I'm guessing there were around 750 people in there. It was great session, and Jeffrey did a great job. Many demonstrations drew spontaneous applause.
The next Beta of Monad is due out in a few weeks, and according to Jeffrey, Monad will appear in WinFX (the framework) rather than Longhorn (the operating system). That means that when it releases, Monad will be available on Windows XP SP2 and Windows Server 2003 operating systems, too.
So maybe Mary Jo got confused or something. The distinctions between WinFX and Longhorn, and what's where on any given day, certainly can be confusing at times. The message I got loud and clear yesterday is that Monad is coming to a platform near you as part of the Longhorn Wave.