Am I missing something or the feature has been postponed? Or someone has this on ToDo list [ :-) ] ?
Nope, this feature has been committed for 9.4: commit 36da3cfb457b77a55582f68208d815f11ac1399e Author: Simon Riggs <simon@2ndQuadrant.com> Date: Thu Dec 12 10:53:20 2013 +0000
Allow time delayed standbys and recovery
Set min_recovery_apply_delay to force a delay in recovery apply for commit and restore point WAL records. Other records are replayed immediately. Delay is measured between WAL record time and local standby time.
Robert Haas, Fabrízio de Royes Mello and Simon Riggs Detailed review by Mitsumasa Kondo