[Dimaz]

Well, once I owned north-western corner of Karan as dom9 Aby and sacced with 12 or so H3's with knives and still even my closest neighbors weren't domkilled. I don't know, maybe I didn't try hard enough, but it seems you can counter dompush if you're prepared for it by building enough temples/priests on the border. And when your efforts become obvious usually good players will try to gang on you. Maybe on smaller maps it can win a game, though.
Anyway, I think these cases are pretty rare and don't need special fix, as it's still part of the game as Executor said.