There are still some big questions hanging out there. The IRS mentioned nothing about like-kind exchanges in prior tax years, which many altcoin traders have been employing for years. It's also not clear what the IRS means by "control" -- if you have access to private keys but not the software to exercise control over forked coins, does that meet the definition?
I already concluded that hard forks have zero value at creation, so it's not too comforting that Bitcoin.Tax seems unsure:
What was not mentioned
Airdrop and forks generally have no markets when they are created, so is there a zero FMV?
