If this is going to be something new, I'd be willing to bet that BMW will have to start measuring and creating a COC certificate for all new bikes/cars, etc.... in the future.
Kind of like when they had to make a "U.S." California emissions variant of the bikes with the cat converter and O2 sensor, that wasn't required anywhere else.
Makes me wonder if the dealers there will start offering the certificate with a "tune up" that would be valid for x number of years and then a re-test for those bike that could be certified.
It also wouldn't surprise me if the older bikes would not pass the test anyway without major modification, like adding a cat converter system/setup new fi controller, etc... That would definately be cost prohibitive.
Like Laitch mentioned it may be cheaper just to pay the tax, depending on how often you have to pay it --- per year I'm guessing.
I'm surprised that the older bikes are not automatically grandfathered in..... like they are here in the states.