I don't see in this thread any description of a Rev A or Rev B BBU.  I have had U-Verse "triple play" service in January of 2010 with the same flawlessly-working BBU, Gateway, DVR, boxes, et al.  The BBU is black or dark gray, about 3 inches thick.  I haven't lifted it enough to see what Rev. might be printed on it.

This may be moot as I am planning to leave U-Verse soon, due to the ever-increasing prices, for our local cable company.  I believe the cable company provides only a modem without any BBU or router/wireless capability so I would love to be able to keep this BBU.

P.S. Our house power went out for about an hour this morning (a rare occurrence) and I just kept perking along on my laptop and my wife on her tablet, working wirelessly and powerlessly.

Bernie