All such offers "are false," warn BioWare. There are no ways into game testing "via any method other than" the official Star Wars: The Old Republic website.
"It has come to our attention that there are multiple individuals and sites claiming to sell testing accounts, “beta keys,” or other offers of access to our Game Testing Program. All of these offers are false. BioWare is not issuing invites to Game Testing via any method other than those we outline here on SWTOR.com," BioWare on the forums.
"We must caution you that these offers are often scams designed to steal your money, credit card information, or identity. While we understand that you are eager to participate in Game Testing, your security is extremely important, and attempting to participate in these offers could put you in very real danger."
Some offer selling access to their Game Testing Program which is "strictly prohibited by the Game Testing Agreement. We closely monitor the activities of all accounts involved in the Game Testing Program, and are quick to notice accounts that change hands."
"In the event that an account in the Game Testing Program does change ownership, we immediately take action to the fullest extent possible, including permanently banning the account from the Service."
Legitimate beta test chances would come from 'firstname.lastname@example.org'.
"You may encounter e-mail scams that indicate you have been invited to the Game Testing Program - please make sure to thoroughly examine the e-mail and don't click any links unless you are sure it is authentic (make sure to expand the information about the sender, and check for spelling errors or other tricks that scammers often use)."
"If you receive an e-mail and are in doubt or are concerned about its validity, please forward your concerns to email@example.com."
Star Wars: The Old Republic releases on PC later this year.