n911 points out that the new tax law specifically disallows crypto-crypto transactions from like-kind treatment starting in 2018. This is actually good news for me, because it suggests that the IRS won't fight it for prior years and I wasn't planning to claim like-kind in 2017. So now I will claim like-kind for the 2017 tax year which will save me a lot.
Note if you do this you still have to file IRS form 8824.
Most crypto traders ignore the issues entirely. This will cost many a lot of money, time, and trouble. The IRS will catch up with those who don't declare their gains - there is a lot of potential revenue in there for them.
This taxation only is applicable to U.S. based exchanges, since you would be entirely operating within the U.S. If you're trading in the U.S, and using an international exchange, then you're only liable when you hit a certain threshold of 10s of thousands i believe. I don't know the exact figure.
All i have to say is, fuck the U.S. and their new corrupt tax bill. This will carry over to the EU soon enough.