Isn't the C extension issue the same for other languages, eg Python or PHP? (I really don't know, I'm not that familiar with Ruby internals)
I think this issue, like Capistrano's, would benefit from having more Ruby coders, which in itself might require a more newbie-friendly approach from the community.
(BTW I hope it doesn't seem like I'm criticizing Jamis' choice - actually I think he's doing the right thing in the current situation, just that if there were more Ruby coders around he might not be forced into choosing this path)
As far as deployment goes, when you can run Windows services for the mongrels, do you even need capistrano? I've been doing Rails for years without it and don't feel like I need help deploying....