9.1 introduced delayed validation on FKs, and 9.2 on table constraints, however neither one has been useful due to lesser-locks on ALTER TABLE being reverted (see http://www.postgresql.org/message-id/1330350691-sup-1@alvh.no-ip.org), preventing the lock benefits during the VALIDATE stage.
I don't see any commits since then about either one. Is fixing this still on the radar for 9.3? Also, is a similar feature planned (for 9.3 or further out) for NOT NULL column constraints?