Recently Blizzard made changes to how queuing for battlegrounds works. Here is the blue post on the subject.
I have had success multiple times with the following method to avoid these lengthy group ques.The matchmaking system was tightened up for premade groups in 2.4 this will result in longer queue times unless there are similarly geared premade groups on the battleground for you to be matched against.
If you want to get into a Battlground quickly, queue up solo, if you want to play with a premade group then expect to wait longer.
1. Get your premade together.
2. Group queue for the battleground you wish to enter.
3. Shortly after waiting in the queue, have your group leader (the person that queued) drop group and drop the queue. Your team should then be entering the battleground immediately after (depending on your battlegroup, on mine single queues are still instant.)
4. Your group leader then single queues quickly for the # BG that you get in and meets up with you.
I've had this work 4 times consistently. What I think is going on, is blizzard is trying to match the gear of your group leader, hence the long que time, so when they leave your raid group or party and drop the que, for some reason the system views you all as single ques or forgets about the gear checking part and you get in the same bg quick.