I've created a Comprehensive List of Over 170 Themes for WordPress 1.5 as a reference point for those of you looking for new themes to go with the new WP. I update the list daily, and have marked which themes have 3 column layouts.
I figured if we're all searching for WP 1.5 themes, might as well post a huge list in one place for reference. A lot of the themes have come from submissions to Alex King's theme competition and the WordPress Codex. I've also just been scouring the net (forums, blogs, etc) to find as many WP 1.5 themes as I can. If anyone knows of any I've missed, please let me know so I can update my list :)
Hope some of you find my list helpful!