I don't get the negative vibes. These backs offer what I wanted back when the P65 came out. They are stupid expensive, but what else is new, they have always been stupid expensive.
Some of the comments remind me of the Republicans attacking the health Care Reform Act: absurdist and strange, fear mongering about Apple leaving your back unsupported. If you don't like the new backs, don't buy them. Their price tag makes that course of action an easy enough proposition.
What Phase should do is have Mamiya make a digital RZ along the lines of the AFi/Hy6. Come to think of it, they should use an adapter system like Blad and Sinar, so that you can use the back on whatever camera you want. That would be an open system.