The rumor that chapter 81 is the last Ouran chapter has been clarified.
Link
Hopefully, with this explanation we all now understand that there is NOTHING out there that indicates that Ouran is ending anytime soon. I suppose this is a good thing, considering that Ouran is quite popular and there's a general consensus there's a lot of potential story left.
(A now a little wisdom from my Dad:
ASSUME = ASS|U|ME
Be wary of assumptions, as they can be often wrong and based on NOTHING but personal opinion)