Depending on the option selected when you got your card you may or may not need a sticker.

Look on the front of the card.  Middle right it will tell you when the *card* expires.  This is not the licence.  This is only the card.

Look on the back of the card.  There will likely be a sticker spot that's actually part of the printed card + room for additional stickers.

If the front of the card does *not* have a future date for the expiry then you need a new card.

If the back of the card does *not* have something stating it expires Dec 31, 2012 or later then you do need a new sticker.

It's very silly.  The card should be good for life.  Then you can just stack stickers on it as needed.  Ironic that the Ministry of Natural Resources has this process in place that really only serves to make more plastic.