Yep, there is a 3rd party one coming out already, and you can also just leave the charge cord plugged in the top as you play as well, which is what we'll be doing for long play sessions.
Besides, who can sit on a toilet playing for more than 5 hours?
This sounds the same as the euro vs Us galaxy S3 smartphones... the Euro ones are faster, but because the US phone shave twice the ram, when you benchmark them, the us phones come out the same or better as the euro models.