Just released a new version of Pas (0.1.14). It now can be configured as an Apache Request handler -- this brings it alot closer to how the 'standard' application servers operate. It now includes an outbout HTML filter so it can support sessions for browsers that don't support cookies. The request handler also has persistience for the registered application modules -- which should speed things up a good bit.
As far as support for Postgres goes, I'm still banging my head against Postgres's support for large objects. I couldn't get an update to work correctly without blowing away the existing lob. The lo_create/lo_open function still fail periodicly, and since they don't work reliabily, I'm not sure Postgres based sessions will be a real option....