More info: This was a premade of about 35 horde on the Kel'thuzad server. We comprised a number of different guilds and were among the better pvpers on the server.
We used no add-on or other tricks to queue together. At the time you queued at the battlemasters and were able to monitor how many instances of AV were being played. We would then queue in mass, force a new AV to start and join together - usually getting at least 30 of our 35 players into the same AV.
The speed run was done mostly for shits and giggles, and to see how quickly we could finish AV. More regularly we ran full honor AV battlegrounds. There we would get full honor and three tokens in between 10 and 13 minutes - usually in the 11 and change ballpark.
The methods used here should still work today (the toughest part is always getting 35 people who can work together).