So I'm getting error TF30172 when I'm connecting to a team project on my TFS server. This is annoying, because I had created the existing team projects a different way, and now I'm trying to add them from Visual Studio 2010. 
Here's the error I'm getting: 
 
I found this comment online by Buck Hodges 
Unfortunately, there is no fix or change that will ever make it such that VS 2010 will be able to create a team project on a TFS 2012 server. The compat patch that you are referencing addresses a lot of things to make working with TFS 2012 from VS 2010 work well, but creating a team project is not one. You will have to use VS 2012 (or the standalone Team Explorer 2012) to create a team project. 
Here's the KB article about a related patch: 
http://support.microsoft.com/kb/2662296?wa=wsignin1.0 
I first thought about installing this: 
Visual Studio 2010 SP1 Team Foundation Server 2012 Compatibility GDR 
http://www.microsoft.com/en-us/download/confirmation.aspx?id=29082 
And then I thought - maybe this? 
Team Explorer for Microsoft Visual Studio 2012 
http://www.microsoft.com/en-us/download/confirmation.aspx?id=30656 
But ultimately? I settled for a two-part system. I manage my team projects through VS 2012's installed tools, and develop using VS 2010; this lets me do all my check ins and outs there.