Blender's coordinate system is different from what I'm used to, in that Z points upwards instead of Y. What would be the simplest way of converting all the world data (so that all animations, texture coordinates, etc still work) so that Y points upwards?
Clarification:
Object positions are defined as matrices, so just switching translation/rotation/scale information in matrices is not a trivial task. (at least it does not seem like a trivial task to me)