ViEmu is a Vim plugin for Visual Studio. I first came across it in http://www.iunknown.com/
It seems to be gaining a little bit of popularity, I had spent a bit of time a while back learning the basics of Vim so I installed it a while back, but it seemed to clash a bit with resharper so I backed out of it again. However, I have recently gone back to it and have remapped some of the resharper stuff.
In fact one of the best things you can learn with Resharper is using the Alt-R (which activates the menu item) and using the keys to drive it from there. It's surprisingly effecient, as is Vim style editing.
Now one of the the things I did to make Vim editing a whole lot better was turn my CapsLock into Esc. ( using ScanMapper from http://www.sellsbrothers.com/tools/ ) I usually disable capslock anyways because its a completely useless key, so it was great to find a good use for it.
For those of you who might be a little confused why anyone would want to use Vim style editing (it is a little bizzare). Once you get the hang of keyboard comboing (much like resharper) you can edit very efficiently. You definitely have to spend a fair bit of time teaching yourself the basics. (worth getting something like gvim to play around )
Anyways, ViEmu is pretty good, definitely worth trying if you want to multiply your resharper jedi powers in another dimension :)