One of my biggest concerns with SMT's is those creating them understanding the legal implications. Feel there is a large chance that SMT's will be considered securities in the US and therefore need to be registered. If they aren't then all sorts of issues arise and this could cause problems potentially for Steem itself. 

Excluding this, I love the potential of new people being brought into the idea of holding and earning steem that may never even know or care about steemit. To me expanding beyond blogging offers much more room for growth.