OK, preliminary version running at
test.wikipedia.org.
I suggest starting at
http://test.wikipedia.org/wiki/Anatomy
which already has the categories Biology and Medicine (see top bar). Following such a
link, you'll go to "Category:Biology" / "Category:Medicine", which
are normal articles, except they have an automatically generated list of articles in that
category at the end.
I still worry that we'll create a mess like we did with the interlanguage links. But,
here, you go anyway.
Magnus
P.S.: This time I'll try to outsmart you all; unless I hear about some real problems
with this scheme in the next few days, I'm going to put this into the CVS! Be warned!!
;-)