We use TFS preview (our service is at dataarms.visualstudio.com).
14.02.2013 i had deleted project "Root Project", "Test Project1" and "Test Project2" as described here - http://social.msdn.microsoft.com/Forums/en-US/TFService/thread/81997146-a64f-43fb-9952-57d71542cd11.
15.02.2013 another developer commited his change 187 in project "DWH Искрателеком". Real change was in few files, that was checked-out before 14.02.2013.
One day later i get lastest version of "DWH Искрателеком" and found, that most of files are deleted in changeset 187!
We think, that deletion of pojects may bring deletion of files in next commit (for another projects).