You have to own the product to join in the beta testing, but if you go to the module/tool you have and are interested in contributing to the beta, click on the Product Forum of interest, then click Beta. If SW has a Beta release, you will see it there. You must apply to join the Beta with your SW ID to verify current Software maintenance exsists, and the recommendation is to never apply a Beta on a production server, but sign up, get accepted, and contribute.
There is a Beta currently for SAM.
Good luck and good Thwacking!