I've been playing around with MSBuild lately and it seems like a really powerful framework. However, the editing of the projects in VS2008 seems like an after thought. I saw that there is MSBuild Sidekick, which looks fantastic.
So are there any FOSS options?
FYI, I know that NAnt is very popular, but I am trying to stick to MSBuild. If there is a better editor for NAnt, that would entice me to switch.