Cool, PostgreSQL 9.0 Final Release Available Now! From the release notes:

9.0 includes more major features than any release before it, including:

* Hot standby
* Streaming replication
* In-place upgrades
* 64-bit Windows builds
* Easy mass permissions management
* Anonymous blocks and named parameter calls for stored procedures
* New windowing functions and ordered aggregates

Some pretty high end features in there for a free program methinks.