Hi,
I'm currently working on my Terragen / Maya pipeline script, which handles import of geometry from Terragen (and World Machine) into Maya as well as exporting camera and geometry animation into Terragen. New features will be handling of multiple terrain meshes and tiling of geometry and textures.
Still a few things to be worked on, but if a brave soul fancies having a play with it (to see if they can break it or not :) ) please message me and I'll send a version to test out.
Thanks!