The bootloader code is required to update the firmware via USB connection. It can connect to a computer just fine and mine over USB presently. Speaking as someone who has a number of these K16's mining in my farm presently.

 If you are not concerned about needing to easilly update the firmware at a future date, and wish to start mining ASAP, I would recommend you ask for your miners to be shipped immediately. It is unlikely you will ever need to update the firmware.

 The only thing I might want to update the firmware for, is if they ever fix the issue with needing to re-plug the fan on the board header in order to get the system to recognize them on boot, however, I'm going to re-wire my K16 rack this weekend to run the fans off 4-pin Molex, so the fan bug won't be much of an issue for me soon.

 If you'd like to update the firmware at some future time on these, you will need to acquire a PiCkit 3 programmer like the one described here. http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1406&dDocName=en538340&redirects=pickit3

 These programmers can be had for ~$40 USD on EBay if you enjoy tinkering.

http://www.ebay.com/itm/Easy-To-Use-USB-PIC-chip-PICKit3-programmer-ICSP-PICKit-3-Full-Pack-From-USA-2-/271261843858