Hi all,
This is more so "if you're lucky" exploit; if your role was selected as a tank prior to 6.0.2 and you queue for dungeon finder in a Healer or Dps spec the dungeon finder will still queue you as a tank; as a disclaimer, this was yesterday prior to restarts so I'm not sure if it's 100% fixed or not.
Additionally, this happened to me so as a result I had to respec to Guardian and un-select tank manually. As a result of this, I would assume that respeccing with tank selected would keep your tank role.
Thanks all.