The good folks over at Automattic is planning on adding a Theme Marketplace for designers over at WordPress.com. You’ll be able to sell your themes there, splitting the profit 50/50. While that’s a huge take on Automattic’s side, it’ll let you reach some 1,7m+ blogs which was out of limits before. There are kinks though, such as you must GPL and release your theme for self-hosted WordPress blogs, and you won’t get any credit in the theme’s footer, which sucks. I wrote an extensive post on this over at Wisdump, and followed it up with a post on design credits, so pop over if you’re interested.