I've uploaded the beta source code a day early. Tomorrow I will be uploading a compiled package with sample code.
Also, keep your eyes on the wiki as it's being updated daily. That's the place you'll want to go to learn how to use Rhyduino.
I've completed the basic functionality that has been targeted for the initial release. It's very stable, but I'm the only one who has tested it so it'll be nice to get some other eyes on the code.
I will be updating the site this weekend to include full project details, and I will make the beta code available on June 1st.