So, I have VS 2010 installed and am in the process of modifying my MSBuild script for our TeamCity build integration. Everything is working great with one exception.
I'm no expert with MSBuild, but I was able to use the information from this link to accomplish the same task:
http://www.hanselman.com/blog/ManagingMultipleConfigurationFileEnvironmentsWithPreBuildEvents.aspx
There is a section related to MSBuild near the bottom of the article. Hope this helps.