Will data science develop into a separate academic field?
At the risk of showing confirmation bias, yes, data science will become it's own field. The primary argument would be an economic one, data science enables a larger return on investment per resources expended than the many alternatives. It is one of the few profit levers left as business processes become more optimized. So where the money flows, the conferences, journals, et al. will follow.

The second argument is empirical, there are more data science education programs, articles, books, jobs, and salary. I have not modeled it, but this mirrors the indicators in Internet technology and enterprise resource planning waves that the industry has seen. Both have given rise to academic "fields". There appears to be strong correlation.

Unfortunately, large academic institutions and societies have an institutional momentum -- so that recognition may be slow in coming.  One could argue in the business world has already settled this with Chief 
Data Scientist Officer 
C-level positions.