they clearly just guessed at this..
Also, why the hell would they waste precious side real estate on an eject button that can easily be placed on the bottom of the case where the 1 person in a month would actually use it.
Furthermore, there is a good chance the battery is in the back. Why would they route a 1 foot long rod all the way to the back of the unit to eject a battery?
I think the battery is going in the front. If you look at the bottom, it looks like a nice place for the Battery on one side, and a hard drive on the other end. The rear of the laptop will consist of the Optical drive, and the main board and components.