At this point, the startup performance of the bus is entirely tangled up in Xerces. I'm having a hard time believing that building a DOM from StaX is going to beat Xerces, but if someone else thinks so, I guess I'm game.
Sadly, there are no Apache-compatible XML databases I can see out there, so my idea of 'compiling' all the XML files to DOM trees in some sort of persistent store seems impossible.
