Could not one argue that, regardless of the value (or lack thereof) of a fork, it's not constructively received yet if Coinbase/Trezor/etc won't support it?

Which leads to an interesting conundrum: if you only receive it if it gets popular, then your basis will invariably be higher than it would have been, potentially leading to more taxes. But if it never gets popular, you'll never get it.

NINJA EDIT: As a separate question, under what category would fork income be? Capital gains? "Other" income on 1040?