So the directory layout would look like:
Visual Studio 2008\
Projects\
MyCompany.MySolution\
Models\
Models.Tests\
Services\
Services.Tests\
UI\
etc..
rather than
Visual Studio 2008\
Projects\
MyCompany.MySolution\
MyCompany.MySolution.Models\
MyCompany.MySolution.Models.Tests\
MyCompany.MySolution.Services\
MyCompany.MySolution.Services.Tests\
MyCompany.MySolution.UI\
etc..
The namespace for each project would of course be MyCompany.MySolution.MyProject.
The question was generated by concern over maximum character path limit of 260. It seems better to me to do whatever I can to be able to freely name my projects and solutions; however, I don't want to run into an unforeseen mess.