A while back I wrote a little about what's changed since beta 2 and the release of beta 3.
Brian Harry, the person who heads Team Foundation (he is Product Unit Manager), has just written the post about what changed. In What's new with TFS Beta 3?, he covers the whole product, as you might expect. You'll want to read it.
One of the things he mentions is something new, tfpt.exe. That is a power toy that provides some very useful features that didn't make it into the regular product. We've been using it internally now for a little while. I'll post more about it when it is available in the next couple of weeks.