Well this is about the best news I've read all day. Microsoft has acquired DevBiz, the makers of teamplain, which provides web based access to work items and some source control operations.
The good part of the news is that now MS owns it and is rolling into Team System (first as a power toy), and as of right now, you can download it and install it for free. So long as the clients have a TFS Client Access License, you're good. [via Brian Harry's blog]