I got 542 HKs in Alterac today, and almost 50 killing blows making me #2 on the Horde side when I finally left. :O
Alterac is fun, but it gets kinda boring since the battle basically goes back and forth between rez waves. There's a bunch of quests inside it, though, which net you almost 7000xp and a few gold each. You can kill enemies and loot their bodies for fun items such as severed night elf heads, tufts of gnome hair and dwarven spines. Then you turn them in for reputation bonuses!
There were a lot of stupid Alliance kids running around solo trying to be heroes or something. On the other hand, the Horde was being stupid at times, too. Everyone was running off to one of the mines to fight and the Alliance would sweep down and capture two graveyards in a row. Then we'd have to fight for 20 minutes to get them back.
I think once everyone actually completes the secondary quests, that kind of behaviour will die down. The Alliance seemed to disappear at times, too, presumably into their own caves.