I think a modular base would mean that VimScript could be entirely replaced with a different kind of scripting language. I for one would love to see Ruby or Python take that spot!
Vim needs to be built with the support enabled, though.
Python: [1] (more info [2])
Ruby: [3]
[1] http://vimdoc.sourceforge.net/htmldoc/if_pyth.html
[2] http://stackoverflow.com/questions/905020/resources-concerni...