I have been using the following reg files to enable/disable the lowercasing in Visual Studio 2012 (Full)and Visual Studio 2013:
http://erwinmayer.com/dl/VS2012_ALLCAPS_Toggle.zip http://erwinmayer.com/dl/VS2013_ALLCAPS_Toggle.zip
Just double click on VS2012_ALLCAPS_DisableVS201x_ALLCAPS_Disable.reg
inside the archive to disable all caps menu titles, and VS2012_ALLCAPS_EnableVS201x_ALLCAPS_Enable.reg
to re-enable them.
You can easily edit the reg files before with a text editor to see what they contain.