The worry for me is that it won't just be a serial number.
At the moment the things can not store any more data on them. It is not compulsory and there are no plans to force it on you. it's a complete over reaction due to a lack of understanding of the technology and a utter fear of the state. Even though the technology has nothing to do with it and if the laws changed to allow what you suggest. The technology would be the least of your problems.