When the whitepaper came out I was not sure what to think of it. Initially my reaction was negative actually because that's not the idea I had of steem as a protocol.
The vision I had is that the steem blockchain would power thousands of websites and that all users would use the same currency. So when SMT's were announced I thought these token would ultimately dimish steem's potential as a base protocol and as a currency.
But, I recently found out ( thanks to @timcliff) that to use these SMT's you need a steem account. Basically every users using these meta tokens will be steemians by default. Take for example the appics coins XAP.
When new users register on appics they will essentially create a steem account which will allow them to use XAP. This means that you will be able to log into appics.com with your existing steem credentials but appics will only display your XAP balance on the site. In other words, steemians will have wallets with hundreds of smart media tokens in them :-)
So why is this big news for steem ?
Because the most important metric in any business is the number of users, when you have users you can create value in hundred's of different ways but if you have value with no users you are pretty much doomed ( most altcoins)
SMT's are the perfect trojan horse to get everyone on the internet to get a steem account.