From my prior knowledge concerning beta testing, its a long, hard process. Sometimes the developers have to scrap everything through a rollback, and you have to go through the WHOLE thing again.
Before you volunteer yourself, think about it, will you be able to deal with the frustration? I know beta testing seems tempting, and it is a fun process, accessing a game before everyone else, but its a grueling process, the game usually is SO BUGGY it makes you want to scream. that's why there is beta testing, you point out the bugs to the devs so they can fix it.
Just think about it before you sign up.