Just stumbled across this LtU resource, July 2009, and feel that D community might learn something from it (sorry if this is olde news) ...

Unladen Swallow: LLVM based Python compiler http://lambda-the-ultimate.org/node/3491

and from there:

unladen-swallow: A faster implementation of Python http://code.google.com/p/unladen-swallow/

Now further looking at RelevantPapers that these folks are citing, it looks like they might actually be quite a tuned-in bunch:

http://code.google.com/p/unladen-swallow/wiki/RelevantPapers

And their project plan makes them look quite serious too.  For example,

http://code.google.com/p/unladen-swallow/wiki/GarbageCollector

I must confess that I've largely ignored Python in the past but there certainly
seems to be some interesting reading here and I suspect some reasons for
D people to become a little more introspective.

Cheers
Justin Johansson