New Post: MSBuildExtensionsPath on 64 bit machines

I apologize in advance for some similar newbie questions, but I couldn't find a clear direction in the online docs or discussion list.

On a 64-bit Server 2008 R2 SP1 machine with Visual Studio 2010 SP1, I installed only "MSBuild Extension Pack 4.0 (x64).msi". Is that the correct install or do I also (or only) need "MSBuild Extension Pack 4.0.msi"? I am using this with VS2010, MSBuild and TeamCity (but not TFS).

"MSBuild Extension Pack 4.0 (x64).msi" installs to the 64-bit C:\Program Files\MSBuild\ExtensionPack\4.0, as expected. However it appears that MSBuild is a 32-bit process (when launched from the VS2010 Command Prompt window), as the MSBuildExtensionsPath* variables have a 32-bit world view when displayed with <Message Text="MSBuildExtensionsPath : $(MSBuildExtensionsPath)"/>:
  MSBuildExtensionsPath : C:\Program Files (x86)\MSBuild
  MSBuildExtensionsPath32 : C:\Program Files (x86)\MSBuild
  MSBuildExtensionsPath64 : C:\Program Files\MSBuild

If that is true, what PropertyGroup and Import statements should we use to access the MSBuild Extension Pack tasks? It seems like we need to explicitely reference the 64-bit install path, however the tasks don't load corretly with these statements:

    <PropertyGroup>
        <TPath>$(MSBuildExtensionsPath64)\ExtensionPack\4.0\MSBuild.ExtensionPack.tasks</TPath>
    </PropertyGroup>
    <Import Project="$(TPath)"/>

The MSBuild Extension Pack code samples imply that the tasks should be copied to a local directory relative to the project (see below). Is this the recommended approach, and if so, what files need to be copied?

    <PropertyGroup>
        <TPath>$(MSBuildProjectDirectory)\..\MSBuild.ExtensionPack.tasks</TPath>
        <TPath Condition="Exists('$(MSBuildProjectDirectory)\..\..\Common\MSBuild.ExtensionPack.tasks')">$(MSBuildProjectDirectory)\..\..\Common\MSBuild.ExtensionPack.tasks</TPath>
    </PropertyGroup>
    <Import Project="$(TPath)"/>