@Matt: Well I have some inside info from one of Microsoft's Partners, Perhaps you would have heard of them? IBM.
The first beta is not scheduled for public use. But I doubt that it wont be leaked.
@Snake: What are you talking about, There are a million ways to replace the start menu. And yes Matt Microsoft did say there would be something like a Pie-Menu.
Hope I answered your questions. If you have anymore, Just ask!
Windows 7 taskbar is the most improved thing from my perspective from this version of windows compared to all the rest. Never before since windows 1 have you been able to pin icons to the taskbar and launch straight to the applications.