Tachikoma on 18 January 2015
There is one currently in development/testing, though not at an aesthetic stage, just a compressive architectural approach at this point in time, mainboard and cooling solutions roughly 35-40% smaller than current.
from the pcb revisions i have seen, one will feature onboard flash in place of a hard drive (but have a slot for one), and the other has no flash so i assume is a hard drive provided sku.
From that i would guess a slim 1tb and a slim 32gb flash for $50-75 less.
Essay Pro