Go check it out!
You need to make a league in their application so that you can have access to the league management interface where you'll invite friends to play with you.
If you'd rather not go through the process of making your own league, I made a short video to show you how it looks:
Huge thanks to the guys over at AKQA and Heineken for working through this with us, I think a ton of Facebook App developers will follow your lead in order to let their users invite non-Facebook members to their applications.
Cheers!