implement a more intelligent merge for xml files (including project files) and sln files
Merging project files and especially solution files is a real pain currently. For solution files, it would probably be better to ditch the current format altogether and replace it with a more sane xml format. The core problem is that projects are numbered, so when 2 users add a project to the solution, you have to either fix it by editing manually or disregard the changes and re-add your projects. It's a pain either way.
Keith Hill commented
My biggest disappointment with VS 2012 round tripping is that Microsoft didn't get a more manageable SLN file format put in place first. Comparing and merging SLN files is an extreme pain in the ****. Often the folks who do our merges, look at the source -> base diff and recreate those changes in the target. This majorly blows! Especially considering that even diffing is hard due to a project numbering system that causes most of the file to show as changed. Plus dealing with GUIDs is not particularly fun either.
Denis Kochetkov commented
+1 It is really hard merge Visual Studio Projects when Visual Studio changes the order of parts of project.
vcproj is more common issue in our company.