I phoned their Technical Support (Google the Corporate Office Number for Trion Worlds, ask them for the phone for Technical/Account Support, or have them transfer you).

I just asked for 4 extra VIP keys to be applied to my extra 4 (already created) Trion Worlds Accounts. I told the rep I wanted to determine if this my computer would handle multiple instances of Rift running on it before I invested the $200+ in Pre-Orders. They won't give you the Beta Keys (the numbers), but they are more than happy to apply them to your account and make sure the accounts are able to play in the Betas.

His name was Morrell (if you run into problems with other reps).

Their hours are 8am - 8pm PST. My wait time in the queue was approx 4 seconds during primetime (GG Blizzard).