Currently OSM has wide support for features that have agricultural output in the form of the key: produce ( http://wiki.openstreetmap.org/wiki/Key:produce ) but little support for output in terms of manufacturing. This proposal aims to further define the two with the goal of providing clear guidance on their continued separate usage in the future.
Nice proposal. Actually product is already in use (apparently for the
same purpose you made your proposal for, but I didn't check this in
detail), maybe there are some mappers on this list who used the tag in
precedence and can explain how:
IMHO this tag was already "approved by voting", as it was included in
your recently approved kiln-proposal, but feel free to have more
discussion on the definition details.