I thought I remember hearing like 4 or 5 years ago that MS was planning on replacing VBA with Python Support in Office apps. But I can't find anything to back that up, so maybe I just had a really wishful dream.
What I think they should do is not just make a python API, but replace VBA with it, and expose it to end users where VBA is currently exposed. Python should be the language of macros and user defined functions.