The theme editor for me takes way too much time and effort...mainly because it just doesn't seem all that easy to get results fairly quickly...like even within an hour.
The idea of having a variety of themes to choose from would be great. I use Mercury and like it best. Tungston has good contrast but is too dark for me. But both are very good and I'd be all for Cake coming up with a 1/2 dozen or so along those quality lines.
The ones the "users" have created are decent but I find almost like a bag of m and m's... just so colorful or some dominant color that I'm not really into... kinda like a "crazy car" paint color....or a "glowing color".
There's one that Caa2....or similar name that is creating one, that I really like and will be eager for them to finish. I'm thinking I might be liking it best almost of all I've seen. It's kinda retro, but relaxing... not dark black with day-glo orange meters and buttons.