My thoughts after finishing up the keynote.
1. .NET desktop development is all but dead. ASP.NET will live on, but the future of desktop apps is WinRT using C#/XAML or JS/HTML. Even Silverlight seems to be on the way out. Did anyone notice him running WinRT-targeting code on the phone?
2. The smaller footprint, insanely fast boot times, and attention to detail (e.g. upgraded Task Manager, taskbar on both monitors) makes me excited to see what else is in there.
3. Roaming profiles in the cloud are awesome.
4. The ability to save a "reset" image is fantastic for home users and OEMs. No more searching for the recovery disc or waiting hours for the recovery partition to install everything. Just click reset and you're back in business.
5. App store listing non-immersive apps is a great idea and is sure to get the number of apps way past Apple's AppStore numbers very quickly.
6. Support for x86 and ARM in new apps without recompiling.