Ah, very interesting list.

I guess I think of Python differently from the other projects in your list because the choice of DVCS chosen by the core team seems to me to impact the DVCS that someone will choose for their library in the language. I don't really have any evidence for that, however.

Do you think that (a) language communities tend to standardize on the same version control, and if so, (b) that language communities tend to standardize on the version control of the core project for the language?