The other day I did a quick tweet-vey asking folks what they wanted to see in MonoDevelop the most. It turned out that what they wanted the most matched pretty much what we had been working on.
About 50% of the features requested will be in our upcoming MonoDevelop 2.2. One cool refactoring tool is bound to the F2 key. You press F2 in a parameter or local variable, and as you edit the local/variable, all the references in your method are updated accordingly live.
There are many more features on the pipeline, but they deserve more than a quick post-and-run.