Asynchronous master/slave streaming replication is built into the database, without requiring external scripts to be configured.
Replicated systems can be set up as Hot Standby ones that allow read-only queries to execute against them.
The control over WAL archiving has been split. In addition to the existing archive_mode and archive_command settings, a new wal_level setting allows fine-tuning of how much information is written to the WAL.
Monitoring of the replication progress made by a standby server that accepts HOT Standby queries can be done using the pg_last_xlog_receive_location() and pg_last_xlog_replay_location() functions.
A new tool for removing older WAL archive files has been provided as contrib/pg_archivecleanup ...
