Update – It sounds like the iPhone 5′s “Lightning” port may not be a true “Thunderbolt” interface. So far the info on Lightning has been extremely vague. Thunderbolt is a 20 pin interface, Lightning appears to be a 10 pin interface.  No one really knows right now.  Apple claims it is an adaptive interface.  Perhaps it can support USB 2.0 signals and a subset of the Thunderbolt interface.  The USB “adapter” may simply align the power and data lines to the Lightning interface.  USB has 2 power lines and 2 data lines.  Lightning has 8 data lines.  Perhaps it can operate with a variable number (2-8) of data lines.  I wonder if they can support