Since when can you queue for two different things simultaneously?
I believe since 5.0.5 you could have multiple ques running. As a tank If I see more than 30 mins in the LFR timer I see if theres a bonus satchel for a dungeon, if so, I pop that que aswell, instantly get in, make my JP/VP from it + extra gold and a present, then leave. 5 mins later, oh look LFR is still in que but the group is just waiting for 1 healer now. There is a secondary drawback that rarely happens in that if the dungeon takes a little bit longer than the que time of LFR you sometimes get it popped while still in the dungeon and have to make a choice of leaving or finishing and re-queing LFR. it rarely happens but still you look like a dick saying, "Oops, sry I must go now my LFR needs me!"