ArsDigita's goal is to spread the religion of the ACS as much as possible. In that respect, Philip has expressed great interest in seeing ACS/pg come about, but he's been quite busy so hasn't been really involved.
ACS/pg is not meant to compete with ACS/Oracle. It is meant to allow anyone to set up a fully open-source, enterprise-quality web application. Open-Source is taking over the world, and there's no reason to stick with the concept only at the Tcl layer :)
In the end, the ACS/pg team and ArsDigita coexist happily. In the true world of open-source collaboration, we hope to be able to push back bug fixes, improvements, and more to ACS/Oracle.
