I was a bit bothered by the noisy look of the front page, so I took a shot at restyling it: screenshot, pastebin. Not insisting that you should use it (I'm using it as a browser stylesheet anyway) but just thought I'd share.
Edit: whoops, this affects other pages in surprising ways. I'll try to fix it tomorrow.
Thanks for this—it's great! I went ahead and tweaked your modification a bit and elaborated on it, and now it's available on GW as a selectable theme (note the theme selector widget at the top-left of the page).
Any further suggestions on improving the theme are welcome! (See here for the grey-theme CSS as it currently stands.)
P.S. If anyone else wants to post or send us additional alternate themes, please do!
Might as well go with a bang.