To answer your question, YES! As far as I'm concerned, #23 has been worn by two of the best players in OU history and no one will ever take their place. I see no reason not to retire the number now.
Thats the way I feel, how do you know another wayman or blake won't come along? Think they should have every right to ask Blake to wear the number as I believe Blake's character would be able to respectfully answer on behalf of Wayman.