For our code review process we open the details of a shelveset to see all files that have been worked on. Right clicking and choosing \"Compare\" works great for existing (
your solution does not work for me. I checked windows explorer and my .cs files are actually associated with VS2008 (so when i double click a .cs file in windows explorer it will open in vs2008, which makes sense) but what is strange is I dont really use vs2008. I use VS2010 as code editor and regardless of the Windows Explorer file association my files are still opened in Notepad.exe (when i compare or view a shelveset and open a newly added file).
I think there must be a different association within visual studio 2010 or TFS somewhere ? (Im on Windows 7 if it makes any difference)