Albert Weinert has release an update to his plugin to allow execution of R# 4.0 from within Visual Studio .NET 2005 / 2008. The only Unit Testing framework supported by R# 4.0 out of box is NUnit, so this is a useful plugin for those who prefer MbUnit to NUnit.

I recall that one of the final features for R# 4.0 was planned to provide out-of-box plugins and support for several Unit Testing frameworks. Wonder what happened to that plan.