Sadly I couldn't stay for all of today's sessions in order to get home at a reasonable time, but I did finally get to meet Rob Howard from Telligent (former Microsoft) after conversing with him for years by e-mail, forums and blogs. Good to finally match a face with a name.
There were really two big stories in terms of product. The first is Atlas, the AJAX framework that makes it very easy to build stuff in ASP.NET. There's a lot there to use with other platforms as well, but it's so easy that I don't know why the hell you'd want to. It's fairly amazing.
The other big story is Windows Presentation Foundation. I personally wasn't that excited about it, and didn't go to any of the sessions, but I peeked in on one of them (The North Face demo) and was impressed. Obviously a lot of people are interested because the session was packed. I kept hearing in the halls that they're planning on releasing it for other platforms, including the Mac OS and Linux. If that happens, it's suddenly a lot more useful.
There were a lot of bigger picture panels and such that I got a lot out of too, including the revenue model thing and the future of Web advertising. The most interesting opinion on the former was about the validity of subscription models, and they all agreed it was still possible to make money that way. Tim O'Reilly has reason to believe that, in that his Safari online service is 25% of the company revenue now.
There's a lot to soak in. Hopefully the heavy drinking at TAO Monday night didn't erase some of the day one stuff. :)