Here's a full set project files and a solution for Microsoft Visual Studio 2005, the same ones that live in the opensecondlife.org repository. The files live alongside the 2003 project files and are named *2005.csproj so they can happily live alongside the current setup. The proper pre-preprocessor definitions have been added to make 2005 act more like 2003 and remove a lot of the compile errors and warnings, and have been in use for some time now.
Just to clarify, all of these files were written exclusively by myself so there shouldn't be any copyright assignment issues.