Well, the community spoke, and we listened, apparently. Team System is going to be awesome, but a lot of individual developers or small developer shops might have found it a bit expensive to justify. So, we're announcing the following:
1) Every copy of Team Architect, Team Developer, or Team Tester will come with a limited version of Team Foundation Server
2) This version will be restricted to a maximum of five users.
3) If you need more than 5 users, you'll need to buy the full team foundation.
So, essentially, Team System and Team Foundation is going to be available to everyone with VSTS Architect, Dev, and Test.