I'd be surprised if Apple itself has a definate date for ending work on Classic Mac OS (here's to OS 18.104.22.168.2! <img src="graemlins/smokin.gif" border="0" alt="[Chilling]" /> ) It'll likely be maintained for Blue Box purposes, receive bug fixes, etc. for a long time yet.
The more important questions (now that 9.x has already been starved of new features or promotion) are when Apple will decide to 1) halt preinstalls on new systems, and 2) stop delivering apps for the older OS.
"Friday, then two weeks after that" sounds good.