I talked yesterday to somebody who was somehow involved in COMAND beta testing.
It seems that US E55 cars can't be retrofitted with the COMAND system because the US COMAND and German (ROW COMAND) are completely different units, even if they might look the same from the outside.
Apparently DC installed a retrofit option to all E-class models equipped with APS 50 but this retrofit option is compatible only with the german (ROW?) COMAND system.
So when the specs for the US COMAND were finished, the unit wasn't compatible anymore with the retrofit.
It also seems that this came as a surprise to DC, one reason why they made that generous offer in the US.
The US COMAND apparently won't have a VIDEO or even TV option, no possibility to play DVD movies.
However...it seems that the navigation system is DVD based, using a DVD unit in the trunk.
The slot above the monitor fits CDs only, not CDs and DVDs as on german/ROW units.

This information came to me from another person, so I can't guarantee that it is correct. I just thought that some of you guys are interested to hear it.

In case you don't believe that COMAND retrofit is possible on german E55: I'll post two pictures of my E55 (before/after) soon.

ROW=Rest Of World