OpenBSD 4.6 is scheduled for release on 2009-10-01. Pre-Orders are now accepted.
The new release brings a new privilege-separated SMTP daemon, improvements over OpenBGPD, OpenOSPFD and other routing daemons, a per default enabled pf(4) that has stricter checking for ICMP and ICMP6 packets, improved driver support and many more changes.
Here is the full list of changelog for OpenBSD 4.6 ■