Really what we need for AV is to not have to wait for faction balance and to get a game going if even 1 person queues up for it. There's a TON of incentives to go into an empty AV, and there are tons of incentives to finish it or just farm a little bit of rep for a while.
In addition, don't shut down an AV when there are 0 people in it, so people can't abuse it to respawn herbs. Just let anyone join and leave as they choose, and when a game finishes, a new one can be queued into. Beyond that, if the first AV is full on both sides then you can open up a second AV as normal.
I can't count the number of times I've queued for AV and just sat in queue endlessly because there's no one else queueing at the same time. I know I can't solo the place to victory, but let me farm some rams or something. People knowing that AV is always open (at least 1 instance of it) no matter how many people are in it would be an incentive for people to queue any time of day and get in there. A guild could queue up, go in and smash it, and get a new one started too. The drawback that I can foresee with this is that it can affect AV morale, and one faction will queue and win a lot while the other will not bother trying to win. Ironically, there is great incentive to lose an AV too, so you will still see a decent number of people from an underdog faction queueing up.
I don't think this translates to other BG's very well because unbalanced games can really affect morale of a faction, and an empty AB or WSG is not fun or challenging at all. However, AV is a unique beast, and it really sucks that there are never any games to play without queueing up on AV weekend... and sitting in a queue for an hour because of faction imbalance.
