And in YYZ it probably varies by the agent on duty.

Over in the TSA forum there's a thread going on (mostly) about this topic. It seems that the experiences are variable so there's no indication that liquids are OK or that they're still highly lethal weapons of mass destruction.

An interesting comment in the TSA thread - if the water is frozen then it's OK because it's not a liquid. I think I'm going to try this. I live close enough to the airport that a frozen bottle will remain adequately frozen, particularly if I try this in winter. Will post an update when I do.