On that note, is anyone here privy to any details or rumblings about plans with Microsoft and Mono going forward? With the CLR opening up, is it reasonable to start seeing some unification going on there, or is Microsoft going to do its own thing on Linux/Mac while Mono goes on its way?

Mono 4.x marks the start where Mono is incorporating code from Microsofts opensourced version. From what I understand, Microsoft will continue to do develop their own thing (.NET) and Mono will probably port most of that into its implementation. In other words, they'll remain separate projects but share some code and strive to complement each other for platforms etc. I'm also under the impression that they'll be takning steps towards a unified hosting API, but that's a vague personal interpretation based on non-official statements and mailing list posts.