It would be more fun if it was at least 5 issues long, I also see the 616 characters inventing a cure. The battle will be long, devastating, but the 616 heroes will simply outclass the 70's era zombies. That's not to say there wouldn't be a struggle.
What I think will happen is that there will be a panic, things will seem pretty crappy. At the current state of things due to Civil War, both heroes and villains will be fighting the zombies.
I see some heroes/villains becoming zombies. But since they're still sentient, I see many of them trying to fight the hunger and the zombies at the same time... some give into the hunger before the cure is found. Some B and C (and probably D) list characters will be killed off, whether because they gave into the hunger or they fell victim to the zombies' hunger.
When the cure's found, the 616 zombies will return to normal and face the horrors they committed as zombies and will have a long, hard road ahead of themselves.
The cure will be given to many of the zombies that weren't destroyed. Since most of them suffered mortal injuries, they will not survive returning to life.
Also, the ones that do survive will be imprisoned and what-not... maybe rehabilitated? They too will face the horrors of what they did, free of the virus' influence. Some will kill themselves, some will probably secretly like being cannibals and be contained.
The rest will eventually be sent back to their own reality, although some will opt to stay in the 616 universe, unwilling or unable to face the judgment of their world.
This will also cause the 616 characters to question themselves, seeing how easy it was for their alternate-reality selves/friends to fall into the cannibalistic madness.