PressWP is offering a free WordPress-based Quality Control blog through which users can track product development, bugs, feature requests and customer issues. The blog comes with integrated add-ons such as domain mapping and custom ticket relationships. A demo is available here.
PressWP launched on September 11th during WordCamp MidAtlantic and, according to developer Matt Taylor, is striving to be a “WordPress.com-like service that hosts only specialty WP application themes.” Quality Control is the first of those themes and a “tweet archive service” is on the way.
You may want to check out RoloPress.com. A Contact Manager built on WordPress and released at WordCampNYC last year.
I think we are going to see a lot more of these SAAS sites popping up powered by WordPress.