So a lot of us have been looking at alternatives, and for me the biggest challenge is that the intersection between "game engine I can use easily" and "programming language I can use easily" is sadly quite small.
That got me thinking: if you started a new commercial ES today, what language does your audience want?
NB: please feel free to share this link, I'll share it on twitter etc. The results will hopefully be interesting and useful.
FYI: I picked the top 10 global languages by popularity, and then cherrypicked from the next 50 or so on http://sogrady-media.redmonk.com/sogrady/files/2015/07/lang-rank-615-wm.png - favouring ones where I have met people that I know are using them in gamedev today.