So far, I like PJedi, but there are a few things that could be improved apon. Undo would be nice, and the copy/paste function could be improved in some way. Oh, and when right clicking, might be an idea to also select the entry that the mouse is over so I know I'm deleting the right one.
What else... Ah, maybe drag and pull an hand and the arm will auto align? No, wait, maybe best in other 3D programs.
But, an exporter also sounds nice. Maybe try and make one for all programs and all versions?
I once experimented with an animation converter way back. With 3D Max r3 I moved a box in an animation and saved it as a VRML, and with the converter I converted the coordinates. One mesh animation mind you, like a flying camera or ship, and not very successful.
But I like the ideas.