Lots of PDC hype these days. Here's a piece an Avalon by Wesner Moise that's still leaving quite a bit in the fog.
My translation of what I am reading from the abstracts is:
Imagine Microsoft would drop the entire USER32 subsystem of Windows and replace it with a brand-spanking-new windowing and I/O engine and a fully object-oriented, managed API, finally doing the long-overdue overhaul and replacement of the foundation of the Windows UI technologies that have, in essence, been with us since Windows 1.0.
.... and create a WOW ("Windows on Windows") subsystem layer, not dissimilar to what we saw in NT for Win16 apps, to support existing apps.