I think it will retain the blog platform capability but it will grow far beyond that.
There are a lot of people developing on top of this blockchain. I can imagine a steem comments plug in (similar to disqus), to promote better quality comments, more apps like SteemPress that integrate into WordPress and existing sites more easily.
Curation is a big deal for many right now, but I think that will get fixed soon enough...maybe not ON steemit.com but via 3rd party apps and services.
There's so much to do here, and there are many economic incentives. It's a complex ecosystem that will take years to understand.
I am sure happy to be along for the ride!