Kind of surprised we haven't seen JetBrains step up with a Mono IDE yet. They've already got the IDEA platform and ReSharper, combining the two seems a logical next step.
Interesting! Going from VS 2005 to 2008 to 2010, Resharper has gone from must-have to nice to not needed anymore for me, since most of the features I relied on have been implemented natively in VS.
I would bet they are bumping up against a developer bandwidth issue. Don't forget, they have about 6 commercial products, plus their own language now (and IDE, natch).
The good news is that the community edition of IJ is Open Source (Apache licensed, IIRC) and there are quite a few existing language editors built on top of it. It isn't a rich client platform à la Eclipse or NetBeans, but I doubt such a thing would be required to win the affections of those who are unhappy using MonoDevelop.
