this was just announced on comp.text.tex:
Name of contribution: PerlTeX Name and email: Scott Pakin <...> Suggested location on CTAN: macros/latex/contrib/supported/perltex Summary description: Define LaTeX macros in terms of Perl code License type: LaTeX Project
PerlTeX is a combination Perl script (perltex) and LaTeX2e style file (perlmacros) that, together, give the user the ability to define LaTeX macros in terms of Perl code. Once defined, a Perl macro becomes indistinguishable from any other LaTeX macro. PerlTeX thereby combines LaTeX's typesetting power with Perl's programmability.
So ... when are we going to have the same feature in ConTeXt? After all, we already need a wrapper script (texexec) to run it, right?