I think they'd have to make the software backwards compatible in a fashion - so that the program could still read and use the "old" content (and its "old" rigging style) as well as read and use any "new" type of content (with any new rigging technology they think of). I think if they axe murdered a lot of the old content and its use in the new version, ... well... the firestorm would be pretty to watch ;) And I doubt they'd want that.

Dreams are just nightmares on prozac...
Digital WasteLanD