We've built this internal tool that, in a similar style to StyleCop and FxCop, validates your solutions and it's project's settings. Here is a screen shot from one of our smaller projects:
View the full output: SolutionCopReport.htm (22.00 kb)
I'll consider open-sourcing it if people are interested in such a tool? Leave comment or ping me on twitter.
I am currently considering an 'EnvironmentCop' - a tool to check your environment's suitability for building and running tests.