The new core theme for Moodle 2.0 is “Fusion”, created by Patrick Malley of New School Learning. The theme is still under rapid development and testing, but you can see the design, which evokes WordPress (in my opinion). Check out the discussion or test it out on your own 2.0 install: http://moodle.org/mod/forum/discuss.php?d=154211.
Melbourne is another great theme available for 1.9 (but Danny Wahl, the developer, is working to align it to the new theme engine in Moodle 2.0). It’s modern and sharp, with a nifty analog clock embedded in the header.
Download it from the Moodle.org theme repository: http://moodle.org/mod/data/view.php?d=26&rid=4019 or try it out at the demo site: http://www.iyware.com/2010/12/17/moodle-1-9-melbourne-theme/.