I was an apprentice piercer for a while, but never became a professional (long story there). Anyways, it had me pretty involved in the body mod 'scene' and tongue splitting was always something that intrigued me. I can understand someone getting it done, and have known someone who has it done. People will think you're a freak, that you're insane, that you're just plain weird. They'll call it creepy and wont even come close to understanding why you'd ever get it done. If you're willing to deal with that (forever) then by all means go for it, but be very very sure before you do.
Good luck, I'd be interested in hearing about it if you do end up getting it done.