Yes, two-way fiat gateways would be really helpful. If only those AML/KYC regs didn't make it hard these days...

As for using STEEM and SBD as real currencies, that is where the long-term success comes for any cryptocurrency. Unfortunately, the only proven success along these lines has come from use in dark markets. So far, this use case is the only one compelling enough to break people's fiat habits. Since there's no self-evident tie to Steemit with these markets, this avenue doesn't look fruitful.

On the other hand...there *is* a future use case that goes hand-in-glove - or tree-in-seed - with Steemit. It's only a matter of time before the Steemit ecosystem gives birth to at least one author that hits in big in mainstream markets. It'd be fantastic if that author volunteered to sell one of his/her new & original works solely for SBD! Given the help-the-minnows initiatives I've seen 'round here, it's certainly plausible that a "Steem-Grown" author would agree to do that.

But of course, that happy event requires convenient fiat gateways...