According to Theme Warrior the approval process took just over two months from application submission to the appearance on the page.
The commercial themes page on WordPress.org was added in July of 2009 and how contains links over 60 commercial GPL theme businesses. Any fully GPL theme businesses interested in submitting their site for this page are encouraged to do so, although the submission email must include a haiku describing themselves to be included.
Did you notice any other new theme shops added to the commercial themes page? Let us know what we missed in the comments.