As you may know, I am a diehard VIM user. Thankfully, Jared, a big F# fan (Jared and I used to work on VB together), has written a plug-in for VS2010 called VsVim which supports VIM emulation in VS2010. If you are a VIM user, this plug-in is essential! I can’t imagine using VS without this plug-in.
To install VsVim, use the Visual Studio 2010 Extension Manager, and search for VsVim in the Online Gallery.
Jared has also released the source of VsVim - http://github.com/jaredpar/VsVim.
As a bonus, the core engine is written in F#!