sam, you are right. Unfortunately i cannot go back and edit my post. I just got a SBB-AD7 in and tested it on a ME46B. I can use the DP out port on the SBB using a standard DP to HDMI cable and it does display an image- however, it is the extended desktop of Windows. I can then set Windows to clone the desktop instead of extend. It is also playing sound on the TV through the DP port. I was guessing that using the DP port on the SBB instead of the MagicInfo port would disable the use of the hardware control (on/off) and I was right- the TV does not turn off like it does if you use the magicinfo port (and special cable).
So if you wanted to, you could put a second monitor on the DP port, you just would not have hardware control.