I think it will happen someday. But only when the people of Canada are ready for it.
Not going to happen Sam, at least not joining the USA that you know. Most posters mention Alberta ,which for some strange reason ,known only to the posters , would be happy swapping a Ottawa for a Washington. Given Alberta is "energy" what kind of energy deal would Washington hand to Edmonton? Albertans aren't that stupid. The big suprise comes when the Liberal governments of B.C. and Yukon, and the NDP socialist governments of Saskatchewan and Manitoba are mentioned. Bad Ontario is conservative and the richest. The only province never to receive stabilization payments. Yet for some reason, perhaps the existence of Ottawa within her borders , Ontario is viewed as beyond having any value. As for the Maitimes, we're keeping their wealth in oil, gas, and nickel a secret.
It's interesting to note that few ,if any, benefits would be in Canada's favour and that several benefits would be realized by the USA .Remembering that the only country ever to invade Canada has been the USA ,and that usually the smaller joins the larger I wonder that some day, after the Republics of Aztlan ,Hawaii, Alaska, Florida and North Eastern Somalia, formerly Maine, are recognized by the UN Canadians might vote 38% for allowing American PAU (Please annex us) delegates to visit Ottawa.:)