Yeah, I have done some research on the subject. Most specs for external BD player/burners that I saw said a single USB connection would provide sufficient power but burning would be limited to 2X instead of, typically, 8X. Also such devices, as well as USB powered external hard drives, may be given additional power by connecting them to 2 USB ports with a USB Y adapter.There are plenty. Just do your research. Most do come with both connectors and an AC adapter port to accomodate PCs that have lower voltage USB ports or unpowered ports but can still draw their power from the same port they use for the data and thus require only 1 USB connection like the superdrive.
There's nothing magical about the Apple superdrive, it's just a marked up 3rd party drive without an eject button.
What worries me about the portable BD players is that most of them have an AC adapter. Most manufacturers of USB powered hard drives, though, are confident enough in them getting enough power via USB that they don't even include a connection for an AC adapter.