The internal view pictures from the FCC ID filing aren't the clearest, but you can make out some construction details in Figures 5 and 6. The box is powered by a Broadcom BCM4704KPB wireless network processor, with a Broadcom-based radio (as you would expect from the "SpeedBooster" moniker). There is 32MB of Hynix HY5DU51622DT-J RAM (with an empty set of pads looking to be ready in case more is needed) and 16MB of Intel TE28F640 flash.
Figure 5: Covers off view
(click image to enlarge)
The USB port is handled by an NEC controller and I suspect disk drive functions might be the responsibility of the Broadcom chip whose number I can't decipher in the lower left corner of Figure 5.
It's disappointing that there is only one USB 2.0 port and I hope that the design allows for the attachment of more drives by using a USB hub. But the User Guide consistently refers to only one disk, so we'll just have to wait until the product ships to know for sure.