Sprint told me (although their word means very little to me) that the hardware revisions were due to supply/quality issues with the LCD screen. Each revision of the LCD screen is incompatible with the previous; they use a different ribbon cable/connector.
Yes and no. The two screens (epson and nova) are incompatible with each other, yes. But the hardware numbers do not have anything to do with what screen you get. We have seen hardware versions 02 and 03 have both screens.