here's a recent thread on that:
http://www.canadavisa.com/canada-immigration-discussion-board/time-for-return-of-passports-anyone-t105030.0.html
I sent mine in on 4 may. As of this weekend my status changed to "Decision Made" in my ecas. As of tonight the tracking number on my prepaid Canadapost mailer is not showing up in the system. But from the sounds of the above thread, expect mail around 2 weeks after your ecas shows "Decision Made"
