VsVim Update Released (Version 0.9.3) (VIM extension for Visual Studio)
blogs.msdn.com
blogs.msdn.com
As I understand it, VsVim is a much younger project that is open source, rapidly progressing and has set itself the goal of being good at the things it does and not trying to expand those too fast.
ViEmu (not having used it!) seems to try and replace more of the VS functionality, while VsVim seems to try and be "vim for the editing, leave as much of the rest intact as possible."
(as a side note, I wonder what motivates people to write plugins like this for fun. If the rage-inducing experience that is writing addins for Office is any indication of what it's like to write plugins for Visual Studio, I'd rather burn off my nipples with a hot poker than writing one of them in my spare time).
Anyway what I love about ViEmu is how over the years it has managed to incorporate things to give it the true Vim experience that VS couldn't do, like search highlighting, easy 'search for word under cursor' etc.
(maybe newer versions of VS have these things build in, I've been using ViEmu and Visual Assist since VS 2003 so I'm not 100% sure any more of what comes from these plugins or what is 'native' functionality :) ).
Both viemu and vsvim have the problem of vim key commands and VS key commands clashing quite a bit.
Interesting side note is that the developer works for microsoft and as a result he cannot accept external patches. Which sucks because this is written in F# and it would be neat to learn some and help out.