Mine arrived! I love DHL.
...I was right, it IS a battery compartment for two AAA batteries.
HOWEVER! There's no contacts built into it. There's also a small cutout for a power switch just above the USB plug, which is also NOT built in. The case looks like its made for a wireless model... but the Choc Mini is NOT.
couple of things so far: The stabilizers are not greased, and are quite noisy. The plate seems thin, the keys wobble slightly when i'm going with them and I"m getting that ping chorus people used to comment about on Filcos (my ninja doesn't seem to get that). The keys are a bit more gritty than my Ninja, but that's probably due to how new they are, so I'll look into that after a bit of use.
The indicator LEDs are a lot brighter than I thought they'd be. Switch lock is fun to play with, as resistant as I was to it in a previous thread I actually like it a bit... As I expected, I do like the numpad where it is. Also due to that, I think it retains numpad completely, holding shift + hitting a key while the numpad is active does activate the standard numpad layer functions. Not all the keys were seated properly, had to push a few down.
*edit*
USB cable seems to lock in place. Having extreme difficulty in removing my USB cable from the socket...