Good news for you guys, we just push factory to release the android 4.2.2 upgrade for the MK808B Model.
Please notice, this just work for the original mk808b with rk903 wifi chipset, we have tested on geekbuying sold mk808b, can upgrade successfully.
Firmware is uploading, wait for the download link
Password is geekbuying.com
And here is the screenshot after you make the upgrades
Get Original MK808B from here: