Oh please, can somebody give me some extra time so I can play with this?  Thankfully we no longer have to call it by its codename, WPF/E, which I found impossible to remember.  Ryan Stewart has a great rundown of what this means and what else was announced at MIX.  There's even an alpha available for Macintosh.

Note that when you play back videos on this thing, you can right-click to use the WM "Fast" playback. Much, much better than Youtube.