I think that the possibilities of growth and diversification element of your question is less dependent on the language per-say and more dependent on the langua

I think that the possibilities of growth and diversification element of your question is less dependent on the language per-say and more dependent on the languages eco-system. Objective C gives lots of options because of this, as does java, javascript and C++. Python is definitely up and coming here because US academia seems to have picked it up, although I think it's slow and I can't work the configuration management elements (I constantly get this egg needs this egg type issues) - still I have just dabbled (for much the same reasons as you!) so I know little. I do know though that there are many interesting projects using python now and that as a language it's very well thought through and powerful semantically.