The creator of Evangelion, Hideaki Anno, is co-directing the next Godzilla movie in Japan, Godzill Resurgence. And because Japan has no concept of caring what makes any sense, and we love them for it, there's going to be official Godzilla vs Evangelion merchandise. No word on any actual animation. No, just merchandise of Godzilla and the anime Evangelion.
You'll have to look through the well known imports sties if you want to get the merch coming out in June.