I noticed in another thread there's a new Obi202 firmware out there (yellow icon in the portal next to a '202 device), firmware version 3292 3932.
Applied the update, then did an XML export comparison. In moving from 3878 to 3292 3932, noticed one new field, RandomDelayRange, defaulting to 30 ("the range of delay in seconds before the first attempt only, minimum 0"), in the section for Auto Firmware Update under Auto Provisioning under System Management.
I presume the real meat and potatoes of the difference in the firmware is something to do with the recent Google Voice/Google+ Hangouts changes, and is not apparent in any one particular new field.
Edit: 3292 to 3932.