The ecosystem is slowly expanding beyond applied disciplines, because when those people need to code something else, e.g. a Web site for their research data, then as usual they try to use the hammer they already know.
I'm really interested in Julia's performance for general purpose application development. It's great that it can work with large numerical arrays very efficiently, but what about large, diverse graphs of small objects like you commonly find in general purpose application development? I think I want a hybrid between Julia and JVM or something.