I have some seriously mixed feelings about this one.
On the one hand I really do hope they make some kind of a sequel.
And I think it can be done without Anno without losing to much magic, Gainax is a pretty damn good animation company.
Granted, even that's a long shot. But I think they could nail it.
On the other hand, A sequel wouldn't work to well.
And While I'd get a prequel, I doubt it would be that interesting. No Shinji, Rei, or Asuka...or Kaouru.
I vote for something like with EVA-R, where it picks up the story some where in the middle (toward the end, at the start) and takes it in a completely different direction.
Now that I think about it, I don't have very many mixed feelings about this. That could be good.
Of course if Gainax or Anno can't come up with something good, better just leave well enough alone.
I asked "And where would you take me?"
At this the beast laughed, tears made of my mother's blood leaked from his eyes.
"I will take you to every place you never wanted to be, and you will hate it."
"Then I will take you to every place you've already been, and you will hate that also."
"Last I will take you to the places you have always dreamed of, and that you'll hate worst of all."