I've mentioned in a couple of posts recently how busy it's been around here lately.  One of the many things keeping us busy over the past several weeks has been upgrading the main Developer Division Team Foundation Server to TFS 11.  We've been using TFS in production on smaller servers (for example the one the TFS team uses) for over a year now but the DevDiv server is the largest single TFS server in the world (I believe) and we wanted to get to the release candidate before we made the big move of updating that server.  A ton of work went into pre-production testing and preparation and it finally went off last weekend.  We've since found close to a dozen bugs that wouldn't have been uncovered on a smaller, less demanding server.  The good news, of course, is that we are fixing the bugs and they will make it into the RTM release.

Buck has written a post about our experience if you want to learn more:http://blogs.msdn.com/b/buckh/archive/2012/06/08/developer-division-is-running-on-tfs-2012-rc.aspx

Brian