From Castle Project users group:

I've just built the trunk yesterday (rev 3812).

Main reason: I needed the BaseControllerTest from Castle.MonoRail.TestSupport.

The build was targeting .NET 2.0, in release, and no tests were run.

You can download it from: http://www.kenegozi.com/Castle_r3812_net-2.0_release_not_tested.zip
Note that it is not tested, so use it at your own risk.
If you're not going production this week, it should not be a problem ...