Joe, it sounds like a cool idea. Feel free to be bold and work on it.
Definitely. I think that at this point "coalition building" is a reasonable objective. We have tons of *ideas*, but I think implementation is going to take somewhat broad-based support. I've been talking to the Teaching Open Source folks (http://teachingopensource.org/index.php/Main_Page) and they like the idea.
Who would be the college for the for-credit class?
We're definitely still in "looking around" mode. As I mentioned, I'm at The Open University, UK, and I brought the idea up with some of the maths people here. But that was just yesterday and now I'm waiting to hear back. A more conventional college that nevertheless likes experimental/innovative courses might be a better bet. (Ideas welcome. CS or mathematics faculty champions especially welcome :)
The Wikiversity IRC channel is always open, and users are generally in there to talk further. You can also bring it up on the Colloquium on Wikiversity.
I anticipate a lot of large-scale issues around "Wiki versus Noosphere" (Noosphere is PlanetMath's hand-rolled collaboration platform). And in the long-term, I wonder whether the PlanetMath/Noosphere project can get folded into Wikimedia on an organizational level. So... there will be lots of things to talk about.