it will not split anything, it will simply create a legit chain and a uselesses one that will eventually die, because it has not enough consensus, and will become the altcoin, the other will be again the bitcoin chain we all know
so there is no two chain ever, as a many believe, that is simply wrong on so many level it's not even funny anymore
Amph is right. However, I don't know if will be possible to send bitcoins from one chain to the other one.