Absolutely ... this wasn't an entirely new "invention," although Apple's technique of cramming their metadata in the spec is definitely novel, although nonstandard.
Mmm, I'm not so sure. If you read the Bluetooth 4.0 spec [1], it's very obvious on page 1047 (numbered 801 in the pdf) the exact advertising format, with its block of bytes for sending data. Sending a UID would be exactly what you would do, as a first approximation. There are actually much more interesting schemes that can be used - say if you don't want your competitors to be able to derive any information of their own from your beacons.
