There has been much discussion here and on other forums regarding the use of a netbook for critical focus for MFDB's. The displays are obviously a MAJOR deficiency of the Phase backs, if not most others, and we are all (I think) struggling for work-arounds, or missing the true potential of our backs by missing focus on too high a percentage of our shots.
I would say this to Phase One: write a "dumbed down" version of Capture One as an iPhone app., allowing the IPhone to be used to convert RAWs to viewable JPEGs, for focus, lighting and exposure review, and possibly as backup storage (store JPEGs to the iPhone, RAWs to the card). The connection could be made using a firewire cable, which, while not as nifty as Leaf's use of bluetooth, would allow users of existing Phase backs to upgrade the usability of their woefully inadequate displays. While shooting tethered in the studio may work (for some), taking a netbook out in the field is a cumbersome, heavy proposition. Clipping an iPhone to a tripod is a far more workable solution than carrying a second tripod and netbook while trudging across the tundra...
If I've missed prior discussion of this here, my apologies.