Not all beta testers become moderators, not all moderators become beta testers.
There are three ways to become a moderator.
Get appointed by the Host
Get appointed by the Administrators
Get appointed by the Staff.
Most are appointed by the administrators, though Greg has been known to make many mods, and many mods supermods.
I was made a supermoderator and #esf channel master about a year ago. VT appointed me on the fly when I asked him to allow me to curb the insanity. Two months later I became the Admin of this forum. Cheeseman was appointed the same time. Chimpbot became an Admin a month later, again by VT. Deverz replaced chimpy by the hand of Greg. Megasaxon is Oktagone Staff, that is why he an administrator.
I selected all of the moderators except X, Nretep and Naz. Naz was suggested by the supermoderators, and X was appointed by Mastasurf because he put in almost two continuous days in Help. Nretep was made moderator by harSens and Masta, because he is knowlegeble in the ways of coding, and is in constant contact with harSens.
And since Cheeseman and I made Hibiki a moderator, I can tell you that he was not selected because of the beta release. He was selected because he knows the forum rules, and has been here for a long time.