I thought they sent you an email to your account email saying what to do. Something about like /testcopy and switch the pater to test instead of live, but I'm not positive. Never been in EQ1 betas. Might try the EQ Support forums. And there's a beta forum somewhere too, but you'd get that in the email also, from what I remember. See http://forums.station.sony.com/eq/
Pretty sure the mail you got saying you had been accpted t obeta also told you that players would be phased into the game on an as needed basis, my guess is if you haven't had the 2nd email with details of how to download the patch /testcopy /betabuff etc then your accounts not yet been added yet, There were a ton of new people in there the other night all milling round clicking through several thousand AA's.