Well, that's an interesting question - and results are no less interesting. Should Canadiens retire Koivu's number? There are good arguments for every one option - perhaps that's why every answer got about 1/3 of votes.
You could easily say, that Koivu was (is) the captain during the darkest ages of the franchise. His Canadiens never made it past second round and when they did - they were humiliated (2:8 with Carolina in the last game of the 2002 series, swept by Tampa Bay in 2004). What's more (and perhaps most important) - his leadership is still questioned. Well, that would say NO to any retirement plans. And, oh by the way - few more years and the Canadiens will have to wear triple digit numbers, cause we're currently running out of not-retired jerseys.
On the other hand, only Jean Beliveau was a longer-serving captain of bleu-blanc-rouge. Koivu is the first European captain of the Habs and, boy, does he have a passion for the game. He beat cancer in 2002, almost every season he's played in was plagued by injuries (only four times in his NHL career he played more than 70 games). In 2006 he had that eye injury. What's more - like it or not - for all the league he's been the "heart and soul" of the Montreal Canadiens. Yeah, if he wins the cup, he will be one of the Greats - but isn't he already? (note - Carbonneau DID win the Cup as a captain - and he's not retired).
Tough decision, but a very interesting topic.