I think there will be a great demand for these servos, I am sure they will be designed to work with any chemistry of a Li cell (3.3 to 3.7 nominal, maybe over 4.2 off charge).

The issue is what about the other servos and devices? This will just add more complexity, as it you really want the 480 ounce inches you will want the full battery rail. So what, 2 rails?

I think ACT has been selling 7.2 volts servos for awhile, there is a market for them I think