OpenBSD releases every half year a new version, usually at 1st of May and 1st of Nov. Now the upcoming version 4.5 has been tagged as BETA which should be available on the OpenBSD mirrors soon. You are invited to check it out and report bugs you find to make this release also a good and stable system.
Reference: OpenBSD developer Miod Vallat tagged the operating system to 4.5-BETA. ■