That's also my problem with it. If, say, Levy had killed Eve, that probably would have worked better. Or some other villain with a more established history with Mark. Conquest so far seems like a "boss" of a level; scary unto himself but in a way just seems to fulfill a plot obligation, to be an obligatory challenge to overcome. Of course I could be wrong; Bane got to break Batman on his first major thing, albeit after a year of subplots, and he went on to be a decent bad guy.
Still, though, Kirkman can vow about it being forever all he wants; he still revived Levy after two years with a very quick explanation. I'm not exactly giving up on Eve yet. That's the thing with creator owned books, they can do or shift however the creator wants. If in 2011 he's found some great way to bring Eve back, he can.