Blizzard may be starting to collect information about accounts wich will participate in WotLK beta key lottery. A new attribute is added to account management page of each account, measuring the account activity
And indeed, if you go to ***.worldofwarcraft.***/login
and log into your account, you will see on the bottom of page (under subscription) stating something like: "Account activity: x.x"
Blizzard did not confirmed nothing of this yet, but guess is that they are building database of accounts that are most active, and that those accounts (with rating bigger that 4.0) will have prio in WotLK beta lottery that is scheduled for mid january.
