the iota devs have set in stone a list of pre-requisites before allowing iota into the exchanges. that is a very sensible and reasonable decision of them, reflecting the true goal of the iota project: the long term real world usage, instead of short term speculation.
as soon as the devs are satisfied, the exchanges will be authorised to offer iota trades, now as a perfected technology (there are great exchanges participating on iota slack already, don't forget this fact).
meanwhile, there's slack for the pre-exchange trades.