The lithum battery is a must in a camera like this. It's the same reason you see rechargable OEM batteries (whether they be Lithium or NiMH or NiCd) installed in the majority of lower end comsumer digital camera's. They arent meant for “power users” or people looking to do professional work.

It actually through me off the first time I used my Flip HD camera and I had to install the rechargable Lithium battery and couldn't figure out how to charge it… (USB port, duh). An internal battery is just one less thing to worry about and that's how it's designed. A no-worry, one button, shoot what you need too, style camcorder.