Maarten asked me a couple of weeks ago if it was possible to put TFS on port 80 along with Sharepoint and if so, was there any documentation.  I said, yes, I know it's possible because I know we've tested it but I didn't know if there was any documentation.  After a little poking around the conclusion was "no", there isn't any documentation on this specific scenario.  So Maarten decided to blaze the path and has documented his experience here for all who wish to follow: http://maartenvanstam.wordpress.com/2011/07/18/team-foundation-server-2010-on-port-80/

Brian