Yes and no. OpenBSD uses four primary repositories: ports, src, www, and xenocara. CVS change announcements are merged for all but ports and go out on two mailing lists: source-changes@ and ports-changes@. Patches are discussed on tech@ and ports@ (sometimes also on bugs@). Also, some key software such as OpenSSH, OpenSMTPD, etc. is developed out-of-tree and lifted into the main train when appropriate. I am not a developer, but I do follow development somewhat closely.