Unless I've missed a big recent announcement, wireless energy transfer, even over a short distance like pocket-to-glasses, is a long way off from being feasible. My money is on a tiny battery built into the glasses themselves, and a screen/CPU optimized for using miniscule amounts of energy. The problem is that wireless data transfer still requires quite a bit of power, so they will either need to do lots of optimization to only transfer data when absolutely necessary (and turn the transceiver off the rest of the time), or come up with a system in which the glasses talk to a central device in your pocket using a low-energy data transfer scheme, and the central device talks to the network over WiFi/3G.
(On second thought, maybe that's what you meant by "bluetooth to a central pack")
With no wires, it's going to be a battery that also has glass on the front. What IS the feasible distance for induction? Even the copin displays require 5v.
(On second thought, maybe that's what you meant by "bluetooth to a central pack")