The Eye-Fi card is a solution for some, but not for a MF backs, since none that I know of have a dual card configuration the way that the Canon, Nikon and Sony do.
Phase P+ backs do have a form of Live Preview, but not on Windows machines, only Macs. That's why many are hoping for a Mac tablet.
The screen on the Kohjinsha, as mentioned several times in the article and video, is fine for judging sharpness in all except direct sunlight, and then a dark cloth or hood of some sort is all that's needed.
Michael