David Lempher's recent blog post (Team Foundation Server...it's more platform than product!) reminded me of a post I wrote earlier this year (Team System Third-Party Products). In that post I wrote, "Team System is a platform for software development innovation."
While Team System has a number of extensibility points, the area that provides the greatest opportunity for innovation outside of the IDE is of course Team Foundation Server, which is why I also wrote, "In my opinion, Team Foundation Server is the crown jewel of Team System."
We're also working on adding more content to the Visual Studio SDK for Team Foundation Server. Visit the Visual Studio 2005 Extensibility Center to download the latest Visual Studio 2005 SDK and be sure to check for updates whenever you're working on an extensibility project.
If you haven't seen it, there's a contest running right now for Visual Studio Extensibility with money and trips to TechEd Spain for the best Add-In and Package built on the Visual Studio 2005 SDK. The contest ends on 7/31, so if you haven't started you need to get busy. For more information, see the Microsoft Visual Studio Extensibility Portal.