I had my solution in Visual Studio 2012 (which is under TFS source control) open and the TFS server (2010) was down. When I then made a change to one of the files and attemp
i found another way without much effort.
Just simply right click your solution and then click undo pending changes.
Next, VS will ask you for acutally changed file where you want to undo or not specific file.
In this you can click no for such a file where actual change is happende, rest is just undoing. This will not lost your actual changes