Ok I had recently posted this in the Exploits section but it got deleted, guess it really does belong in this section instead :P Sorry about the mistake.
The other day I got the T5 gloves token off Leo in SSC. I already had my T5 gloves so I got it with the intention of turning it into the PVP gear vendor at Quel'Danas for the S2 Merciless Gladiator Gloves. After doing so I realized that I already had the S3 Vengeful Gladiator Gloves. One thing to note is that turning in either a T5 token or a T6 token still gives you the S2 gear.
Therefore, since T5 and T6 can be turned into S2 gear, I got the S2 gloves. I then put in a ticket claiming that I had accidentally turned in a T6 token for the Merciless gloves and meant to get the T6 gloves. After a while I talked to a GM and explained that I turned my token into the wrong vendor. The ticket was then escalated. 5 days later I got an in-game mail with my T6 token in it! One thing to note is that this does use one of your item restores that GMs will do for you, so be careful if you have had items replaced before.
1. Get a T5 token from SSC or TK.
2. Turn the token in for PVP token at Quel'Danas vendors.
3. Put in a GM ticket stating that you turned in your T6 token into the wrong vendor.
4. Wait for GM to send you a T6 token after a few days via in-game mail.
Things to note about my success: I have raided Hyjal before, but I have never killed the boss that drops the T5 glove token (4th boss). I am only stating this because there is a chance Blizzard may have checked to see if I had a saved raid ID for there (however, at the time of this I was not currently saved to Hyjal for that week). Also, after obtaining the token, turning it in, and posting a GM ticket, I never logged out or deleted my WTF folder or any cached data.
I have shared this with several friends and guildies who have also tried it and had success.
Further Possibilities: Using this idea, it may be possible to simply acquire pieces of Merciless Gladiator gear via arena points (or with honor points after s4 goes live!) and then place a ticket making the same claim. Similarly, it may be possible to do the same with the bracer/belt/boots obtained with honor points that are also obtainable by turning in a T6 token.
Let me know if anyone finds this useful or has any other ideas to contribute. I know my guildies were a little jealous that I was the first to obtain T6 before it was available to us. :P