I saw the discussion that people just don't think the idea of reactivating the MU sub theme plugin was a good idea. I've seen the child themes too. However, I have the feeling that people talking about it aren't thinking in a larger scale. I strongly disagree that the best solution is not doing it.
I work for a company that desperately needs a plugin similar to the MU one where you can edit the themes in the admin for each client. Because keeping around 12-13 child themes for these clients is a pain in the butt. And when you have logos to put in extract, it makes it more painful to do it through pure .css. I'd also like to give the option to each client to have a different theme without it screwing up.
Who is superadmining this stuff? I am. It's insane once it gets up to 20 to keep the files straight--I rather do it through the WYSIWYG for each client rather than the superuser section.
So I propose two fixes for the dilemma--let me keep one theme labeled for each client in the admin section, or bring the theme editing for the admin back. (or you could do both and instead of saying it's a horrible idea, let the superadmin person decide that themselves after posting all the ideas why it's bad.) If you integrate a sane way to also limit it to a child theme for the admin, I'll be in heaven.