I wrote a quick ut2004 server monitoring app for my own uses, but I figured it may be useful to others.
It's beta, but it seems to work just fine for me. However please report any issues or feature requests to this thread (for now).
For now it requires .NET 4, but I'm going to work to lower that requirement if it's requested.
You can grab the installer here: http://stuff.nvdesign.net/2k4ServerWatch.exe
I fully stand behind open source standards, so if anyone wants the source to the app just let me know!
Screenshot:

Go Sal!!!