I just entered a code (on my Trion/Rift account) that was given to me by a friend who plays TF2 and got the Riftwalker achievement today.
I got this response, "We are unable to redeem your voucher at this time. Please try again later."
So I am hoping that Trion hasn't activated the codes yet, because if they are active then either me or my friend wrote the code down wrong.... and that would suck.
Anyone else try to enter one of these codes yet?