Not that I’m aware of, no. A few people have discussed it but nothing concrete has emerged. We’ve been trying to implement some of the low-hanging fruit among the R# features that matter to people, such as the camelCase completion list matching – please file enhancement bugs if you can think of any more!
Also, now that MonoDevelop is no longer GPL there’s the possibility that JetBrains could actually implement a R# addin for MD, if there’s enough demand. R# as whole is immensely complex, so I don’t imagine anyone else could build a decent equivalent any time soon.
UPDATE: There is an experimental Resharper-like source analysis and quick fix feature built into MonoDevelop 3.0. It can be enabled in Preferences.