There's a really good interview with Trey in the new issue of Guitar World. A few particularly interesting bits of info that came up...
1) He doesn't actually use his Dean sigs anywhere on the new record -- he did everything with his Ironbird and Universes.
2) He actually uses 9-46+56 strings...not the 13s a few people on the web had mentioned him using.
Did he actually killacop?