Recently I've been working a lot on REV-0.6 (You can checkout SVN for the latest revision). Most of that work has been on the new material system and the new models format (rmd). Now both of them work, and I can say that most of the functionality that was present in REV-0.5 works now at REV-0.6 at svn. However this version is not ready yet for a big release because I still plan to do major changes to other subsystems.
Anyway, I wanted to say that rmd models loading is up and running. This format is easier to expand and loads about 3 times faster than rms or obj so it will be the standard for Revolution Engine now on. Support for animations is planned but not working yet. You can download the new obj to rmd converter from downloads tab at www.revolutionengine.tk
One of the add ons of this new format is the ability to load models that use more than one material. check the wiki at google code to learn more of it.