Joel,
We don't have plans for SoapUI at this time. I notice that SoapUI is written in Java and VersionOne has a Java SDK. Beyond that, I'm not familiar enough with the product to offer more specific advice on how to integrate.
You might want to be in touch with our services group who have expertise in building and customizing integrations. Through services, we offer pairing/mentoring as well as API and SDK training.
Ian Buchanan
Product Manager for Platform and Integrations