I also doubt Apple will introduce an user removable battery in the next iPhone, even more considering that the only evidente for that is simply this small hole next to the mini jack connector. That hole could also indicate the presence of a led light for notifications. Or it could mean absolutely nothing because it is there for prototype designing reasons.
The EU is passing laws that require all cell phone for sale there to have a removable battery. Apple is not exempt, nor do I believe they would make a special "EU only" iPhone.