PostgreSQL 8.0 (now in beta) is advertised to come with a revamped, "next generation" PLPerl:

New Perl Server-Side Language

A new version of the plperl server-side language now supports a persistent shared storage area, triggers, returning records and arrays of records, and SPI calls to access the database.

Little documentation yet - the project is in need of documentation writers - but from a quick read of the sample file plperl-test.sql it looks like the interface is simple and intuitive. The projects is in need of more hands and general beefing-up, though.