Educational technology includes a broad category of subdomains. Therefore defining what an Educational Technologist does is not a simple task. However, here is a brief explanation I gleaned from some recent research on this emerging role of strategic importance...

“Flexible technology-enhanced learning environments, both educationally and institutionally are key enablers for delivering efficient ... education. Educational technologists make significant contributions to the development and organizational embedding of such environments. Their emerging role is complex as it requires current knowledge and skills in learning and teaching, management and information technology” (Shurville, Browne, & Whitaker, 2008). [italics added for emphasis]

References

Shurville, S.; Browne, T., & Whitaker, M. (2008). "Employing the new educational technologists: A call for evidenced change" (PDF). Proceedings ascilite Melbourne 2008.