We (the Einstein Toolkit community; see <http://einsteintoolkit.org
>) are examining / experimenting with new file formats for our 3D simulations. As part of these experiments, we also want to examine how they integrate with visualization toolkits.
I have forked yt on Bitbucket <https://bitbucket.org/eschnett/yt
>, and am working on a new front end. At the moment, I cannot make any promise as to whether this will work out, but I thought I'd let you know anyway.