Just got back from lunch with a group from Apple.  After checking the rule book, it turns out that no physical laws would be violated by having Apple and Microsoft so close together, and than fully there was no matter-antimatter reaction :-).

They were interested in Avalon, erm ... Windows Presentation Framework, which was not really surprising.  More interesting was their interest in Indigo, erm ... Windows Communication Framework.

Outside of that, so  far there hasn't been a ton of questions about CAS, however we've answered several questions about ClickOnce.  The Smart Client story really seems to be interesting to people ... and I'm pretty excited about that since I think the combination of WinForms + ClickOnce for now, and later on ClickOnce + Windows Presentation Framework can make for pretty compelling applications without the annoyances of web based applications.