Please don't confuse POE with the rest of your question
Any network device (within reason) can by powered via POE. IEEE 802.3af defines the standard which basically utilizes unused pairs in the Cat5e cable to run power to the device. Some devices (for example IP camers, phones, WAPs) are able to extract the power from their RJ45 port directly and power themselves. If your device can't do this, you can still use POE. What you need is a bit of kit (de-injector?) which plugs inline within the network cable that passes the network pairs on to the device's network port, but extracts the power from the other pairs and provides that as a DC power feed to the device. As you have correctly spotted, there are wall panels available that can do this for themselves.
The Orbiter, however, will be the same as any MCE device, regardless of power. If it's CE-based I'm guessing Thom's magic will provide the software to it. I don't know if any of the dedicated orbiters run PXE, or if they all have the software flashed into them (like the WebDTs etc).
Even if there are no panels currently supported by MCE that are capable of native POE, don't overlook the option of extracting the power from the cable and providing it that way to an otherwise perfectly good panel.
'tis what I intend to do!