it's quite complicated to digest the economic side (incl this post!), but to me the important factors are in the continued development that we can see with explorers like steempeak and that we support projects like steemworld.org which work to enhance the experience of steem so much.
I see fantastic growth, as long as the platform can evolve/improve to bear the demand of increased adoption.
If it ever becomes slow to use, like I find facebook has become, then it'll be bad.
There is a lot of development going on and it is going to get to a point (already now) that it is nearly impossible to keep track of it all. This will of course open up new avenues for more people to take part.