There has been some confusion and a few mixed messages coming out of Microsoft since the release of StyleCop, most notably around extensibility support for the tool, and licensing. We've gotten a lot of great feedback from the community, and in the last few weeks there have been some good discussions between various teams internally about how to position this tool, and how to best support extensibility.
Brian Harry, a Technical Fellow leading the VS TFS team, has recently written a great blog post explaining the context of these discussions and the decisions that have been made. You can read it here: http://blogs.msdn.com/bharry/archive/2008/07/19/clearing-up-confusion.aspx.
I would like to personally extend a big thank you to everyone who has taken the time to give us feedback about this tool. It's been very valuable and very much appreciated. A big thank you also goes out to Brian and others in the VS team who have been working hard to solve the issues around this tool.
We will spend the next couple of weeks getting the next version of the tool ready to ship, and getting all of the documentation ready to publish, and we'll get it out to you as quickly as we can!