I've seen your work, including the Netsparker integration with TeamCity. I commented and mentioned Burp Suite Professional in headless mode might be more appropriate, but fully automated testing in this way only finds a few of the bugs. It's a classic test automation problem.
However, if you do have known HTTP requests that produce a non-desired (i.e. vulnerable) HTTP response, you can use W3AF's export request feature, available at the bottom right of the Results->KB Browser->[Knowledge Base specific item drop down]->Request->[Buttons at the bottom]. This will open a new window where HTTP requests can be converted to test cases. The test cases are available in HTML, Ajax, Python, and Ruby.
Depending on your build server environment, it may vary how to integrate these scripts. HtmlFixture, available in FitNesse, would be a good candidate for the HTML or Ajax request scripts. Under Python, perhaps Nose would be suitable; Ruby has Cucumber.
The book, "Security on Rails" has entire chapters dedicated to this topic -- and separates tests logically out to unit, functional, integration, and browser.
The O2 Project from OWASP has menu options under "API / Script Development" to execute and write unit tests. These unit tests are written in WatiN, but a lot of the work has already been done for the test developer.
If you want to develop something very powerful on your own, I suggest you look at Geb, which combines the browser driving features of WebDriver (and therefore can work with Internet Explorer, FireFox, Chrome and HTMLUnit) with a jQuery inspired content navigation/inspection API and the expressiveness of Groovy.