I've heard the bg situation is turned after 60 on my server. The allies really own the high level bgs. I just got 60 so I don't know first hand, but I've heard plenty of warning from my high level guildies that you should get all the marks you need before 60. One theory I've heard for this is that instead of wasting their time trying to farm honor at lower levels, the allies wait for higher levels where the honor's more per kill.

I've also noticed that when doing AV, there were only been a couple times it's 40 on 40, mostly it's 40 on 20 in favor of the horde in the 51-60 bracket. I don't play AV all the time so it may be that I keep catching them when they're breaking from bg.