I don't think it'll be too great tbh. I'm sure that if it is ever released they'll over look many important aspects of Neon Genesis in the attempt to "cram" as much action as they can, be it the full series or a segment of the series into a single film. To be more direct NGE is more about the themes in the story, like Shinji's mental/emotional sickness or disorder and how that affects him from fitting into society etc. I could see them making a massive cock up of that and transforming him into some kind of Angel killing brash American kid running around in Eva's with 2 hot chicks in a massive mess.
I'm preparing to be disappointed. There's so many things which will go wrong and so little that will fit into place.
Oh and finally the other thing I won't be able to stand is seeing 14 or 15 year olds on the street saying "Neon Genesis is cool" when actually they won't know the first thing about the series, how it was intended to be interpreted or any of the above. They'll just start liking the movies and lumping it with Transformers and any other live action movie. Call me cynical but it's going to be ****. :(