First of all... it's a lot bigger than what I knew.  It's going to take me a while to digest it all and really understand the whole picture.  Today, I looked at the part that I originally was looking forward to the most: source control.  I only played with it for about an hour and I know I haven't seen everything. The most important part was that I was able to setup the security for a user to access the server and then I created a workspace. I then created a new solution added it to source control and started playing. 

The integration is slick.  I've never been a fan of source safe integration with visual studio.  It works ok in small environments, but breaks down quickly with lots of people, especially when working with remote users. Of course, I haven't checked out either of these problems with team system, but in general the integration is much improved.  For example, If I start editing a file, that file is added to my pending check-ins.  The system will track all the files that I've changed.  This is a pain with VSS.  Then, when I'm done editing all of my files and am ready to push this back to the server for a final check in, I just type a comment and click the check in button. 

I spend a decent amount of time synchronizing my files with source safe every day currently.  This feature alone will save me time.  Very nice. 

As I said... Team System is big.  Look for more posts soon with more comments as I wrap my arms around it.