Based on this Issue on Steem's Github one can assume that the way we earn STEEM won't change.

It will remain the main token of the blockchain, thus the bandwidth will be calculated based on vesting STEEM (as you said in the video, user will have to have Steem Power to perform operations on the Steem blockchain).

Developers will have the ability to define which SMTs are accepted to vote for a given post, but Steem Power will always be used along with them.

I might be wrong, I've just started digging deeper into the progress of implementing SMTs. It might be worth to ask someone working for Steemit Inc.