I pulled these from Ewald Hoffman's Customize Team Build 2010 - Part 4 post and posted here for easy reference. Note: you will also have to add a project reference for the code files project in your solution. See Ewald's posting for how to do all this.
Assembly
Location
- Microsoft.TeamFoundation.dll
- Microsoft.TeamFoundation.Build.Client.dll
- Microsoft.TeamFoundation.VersionControl.Client.dll
- Microsoft.TeamFoundation.VersionControl.Common.dll
- Microsoft.TeamFoundation.WorkItemTracking.Client.dll
c:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\IDE\ReferenceAssemblies\v2.0
- Microsoft.TeamFoundation.Build.Workflow.dll
- Microsoft.TeamFoundation.TestImpact.BuildIntegration.dll
C:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\IDE\PrivateAssemblies
- Microsoft.TeamFoundation.TestImpact.Client.dll
C:\Windows\assembly\GAC_MSIL\Microsoft.TeamFoundation.TestImpact.Client\ 10.0.0.0__b03f5f7f11d50a3a
Also add:
- System.Activities
- System.Drawing
- System.ServiceModel
- System.ServiceModel.Activities
- System.Xaml
I also ended up adding:
- Microsoft.CSharp
- PresentationCore
- PresentationFramework
- System
- System.Activities.Presentation
- System.Core
- System.Data
- System.Data.DataSetExtensions
- System.Xml
- System.Xml.Ling
- WindowsBase

Open attachment below to see larger image
NOTE: additional step I had to take on the build machine:
I had to copy the Microsoft. TeamFoundation.TestImpact.BuildIntegration.dll assembly from PrivateAssemblies to PublicAssemblies for the team build to complete without error. Also note that I had set the copy local parameter for all references to false. It was interesting that by default they were all false except for this dll, which I changed to "false". I did not expriement with what would happen if left it set to "true". My client machine is Win7 64x.