Orion, it goes by the howey test. I think the only reason that Dash might pass the Howey Test is not because it is a "currency"... it has a governance structure, it has other features that the DAO has. The thing that might exclude Dash would be that it had no ICO. There was no capital raising round, it was just a code launch where people mined it. However, because of the initial mining scandal, if there was "management" involved in that where they mined themselves many coin, it actually could revert back to falling under the Howey Test and being a security. Only a lawyer could tell us really.
With EOS I have no clue. They called Ethereum a currency... but Ethereum had an ICO, and is effectively governed by the Ethereum Foundation, and is not really decentralized. The hard fork just kind of proves that point.
Ethereum specifically launched in Switzerland to avoid the SEC, so that the SEC would basically call it a currency and not a security is a little odd to me.
In the US, I cannot issue a bunch of tokens to people in exchange for capital, and then launch a cryptocurrency from it. It is just illegal here in the US. So maybe it's a different law that falls under besides SEC securities laws... no clue.
RE: SEC Regulates Tokens