News of the Blizzard Authenticator isn’t necessarily bad, however. There’s no plan to expand this security to all accounts for free.
We currently have only the intention of releasing the authenticator to provide an extra layer of end-user security for those interested in purchasing it. The idea is not to punish players who do not purchase [...]

BLIZZARD® AUTHENTICATOR OFFERS ENHANCED SECURITY FOR WORLD OF WARCRAFT® ACCOUNTS 2008 ANNOUNCED

 
Keychain token generates unique codes used to help prevent unauthorized account access IRVINE, Calif. –- June 26, 2008 -– Blizzard Entertainment, Inc. today introduced an optional extra layer of security [...]