That is interesting, because essentially it is recognising cryptocurrency as a form of legal tender. It also seems to imply that losses would be tax deductible. It is, however, problematic in that it would force you at some point into USD to meet tax obligations, and that implies that there will be a key period when a lot of US sellers will be moving at least part of their cryptocurrency into US fiat as part of a forced sale. Sounds like a good moment for non-USA residents to time for buying into the market.
RE: Cryptocurrency 2017 Taxes: Uncle Sam Wants His Cut