Themes

I should add regarding the notion of using theme's as plugins that there are still PLENTY of dark corners to that plan. For the more basic operations like overriding images, custom JavaScript things work well, the theme system has been designed to cope with those things nearly completely automatically. Other areas such as settings pages, lib file functions etc require more work to utilise, and renderers are cool but as discussed above they still need development, and we still need to convert much of Moodle to use them, unfortunately a job that will likely take years.
Whilst I'd love to promise the world when it comes to theme's and output I simply can't, Moodle 2.0 has been released and presently we arn't working on any new development or improvements to Moodle core, all efforts are being put into fixing immediate bugs and in-house projects such as the migration to our new versioning system (Git). Because of this new development will likely move foward slowly for the next couple of months, I would suggest that if there is something out there that you really want, produce a patch for it.

Cheers
Sam