I'd just like to update this post by saying that you only have
two days left to submit your theme to our
Moodle Theme Contest. So far, I'm seeing some nice themes being submitted, but I want more!
If you need inspiration or parent themes for your last minute project, I've just this week committed two new themes to the core:
Binarius is a native two-column theme that makes liberal use of CSS3 for your webkit and gecko browser users. The effect is really quite nice, I think.
Arialist is a very simple and clean two-column theme that has a settings page allowing users to change the anchor color,
upload a logo, add a tagline, etc.
The idea here is to get a broad spectrum of themes together for the Moodle core that really showcase what the new theme engine is capable of achieving.
Let me know if you have any questions.