While Matt Mullenweg was in Argentina for WordCamp, he announced that Automattic plans to set up a marketplace for theme creators to sell their creations.
So far the only real detail released, which even it might not be set in stone, is that 50% of the sale price will go to Automattic for creating, updating and hosting the marketplace.
This could mean huge revenue increases for them, and the ability to further promote WordPress and the secondary products, like Gravatar, and Akismet.
If you have been creating themes to be sold once on Sitepoint or a similar forum, hopefully, this marketplace will allow you to sell your theme numerous times, and bring in a fair income.
You can read more about the WordPress Premium Theme Marketplace at Blog Herald, as well as my concerns and opinions on the whole endeavor.