Vanguards/Debao/Diziet's team; Sushi - http://us.battle.net/wow/en/arena/dragonmaw/5v5/Sushi/
Nevz alt's Team; LoL... Wait what?; The link to this teams armory seems broken because of invalid characters in the name, but they are currently at the top of US Reckoning BG ladder - http://us.battle.net/wow/en/pvp/arena/reckoning/5v5
The team Sushi has purposefully traded losses to the team Lol... Wait what?.
The team Lol... Wait what? had climbed the ladder to a position close to rank one, and then once reaching this rating, organized games with Sushi, who lost to them, so that Lol... Wait what? could take the rank 1 spot.
Here's a few screenshots of what initially went down;
First Game Win-traded
Second Game Win-traded
Third Game Win-traded
Fourth Game Win-Traded
"Sushi" had nothing to lose by organizing this trade, since they hold rank 1 in 3v3 by a large margin, so can afford to lose rating in 5v5, to the team of "Lol... Wait What?".
When they traded with each other, neither team was playing with their actual line up, Team Sushi traded without Vanguards (the ret paladin they played all their games with) while "Lol... Wait What?" queued without a mage (who had played all the games up until that point) and instead played with TWO priests (this is one of the main indications that they intended to trade, playing with two priests in one 5v5 team would greatly hinder their ability to climb the ladder, especially when queuing against top-notch teams)
http://i.imgur.com/TWSol.png - Both teams playing comps they don't usually play while they trade.
The reason they traded with two priests on the team, is because the mage on the team Lol... Wait What? has really low 5v5 mmr: http://i.imgur.com/qbWVz.png
The team mmr, despite the mage's mmr, is 2754.
So if you factor in the mmr gain from the second priest (around 2.5k+ mmr) they would have a much higher team MMR than 2754, so when they traded they would gain upwards of 20 points a win from Sushi.
Another thing to note is that "Sushi" has not Q'd 5's for MONTHS and the first time they all log on and Queue 5's, they vs the (at the time) rank 2 team. This means that they clearly ARRANGED to play with each other, which is "selective Queuing" and is against Blizzard's rules.
"Sushi" also picked up some random priest (most likely with High MMR) to play with them, instead of their own team mate "Vanguardy", who they had played with all season long.
http://i.imgur.com/ER38T.png - this priest
Following these initial trades three members from the 5v5 team Sushi; Venoma, Diziet and Alex
traded with 3 members from the 5v5 team Lol... Wait what?; Zephcow, Worstlock, Worstspriest
They were repaying the favor, by attempting to feed Venoma and Diziet into personal rating range, so that they could receive the rank one title from the 3v3 bracket in their team Sushi Day: http://us.battle.net/wow/en/arena/dragonmaw/3v3/Sushi%20Day/
Both teams vs each other 3:14 a.m - http://i.imgur.com/L5ABp.jpg
Same again; 3:21 am - http://i.imgur.com/wml53.jpg
Nevz's (Zephcow, worstspriest, worstlock) team goes 0-3 - http://i.imgur.com/C9yPF.jpg
The funny thing here, is that the rank 1 3v3 team, Sushi Day, had not queued for months, sitting on the rank 1 spot on the ladder. Then today, they just happen to immediately queue into the players they traded with in 5v5 only moments before.
So lets recap on all the things they've done:
1 - Win-traded; Both teams were online for about 3 hours Queuing and the only teams that either team managed to VS were themselves. Note: They Q'd at 1AM and onwards, hoping to avoid legitimate 5's teams. Following 5v5 they traded 3v3 wins.
2 - Arranged to Queue against each other.
3 - Also possible ACCOUNT SHARING - Look at "Worstmage" armory page http://us.battle.net/wow/en/character/dragonmaw/Worstmage/statistic#21:152 , a whole host of new achievements and his highest 3v3 Personal rating - 2282. A 2300 player becomes a 2700 player over the course of 2 days. (Most likely affiliated with Arena rating selling websites).
We also have reason to believe that the shaman "Zephcow" , "Worstpriest" and "Worstspriest" are account sharing as well.
Here's a link to the original post on Arena Junkies:
It is much easier to read and view all the images this way.