Experiment: an A/B or Switch Testing framework

I've been reading and thinking a lot about Lean Startup lately, and the techniques and technology and infrastructure required for those techniques.

One of the great concepts, "validated learning" can be accomplished via A/B testing: pushing out a change or feature that some users get and some don't, and then measuring the success of that change.

I consider this an experiment.  So I decided to start to build a little experiment framework, in Java, that will (eventually) also have a RESTful web application element to it to be able to create and consume experiments.

At this point I'm really trying to focus on a clean, easy to use API.  I've also added persistence out of the box and am doing database migrations with Liquibase and persistence using Spring JDBC (partially because I'm a little sick of ORM...)

I may use the experience to try out some different persistence technologies as well, but I've got a little more work to do to create a little web app that can be exercised with RESTful web services first.

Would you use it?