http://microsoftpdc.com/

I just watched the second day keynote and Silverlight 4 looks amazing.

Mic support
Printing support
HTML support (you can embed Flash videos in Silverlight apps using this)
Webcam support
Customizable window chrome
System tray notification support
10% faster startup time
30% better performance for common scenarios
Hardware peripheral support
COM automation meaning you can take advantage of Office API's for example
Full support for Google Chrome
Direct TCP transport support
Full access to the file system
Right click context menu customization
Elevated trust support

^^^And this is all just off the top of my head, no bullshit.

If you're a software dev by trade, how can you not be excited about working this stuff man?