I worked in the aviation industry for nearly 40 years, so I can speak with some aurthority on this issue. I can tell you for certain that if you're caught on board smoking OR vaping, it's treated the same way. I have been present when a vaper was hauled off an Air Canada flight in handcuffs. for vaping in a toilet. The Flight attendant saw "smoke" when the passenger left the bathroom, and challenged him. He immediately pulled out an e-cig, and proudly stated he wasn't "smoking", he was "vaping".
The flight attendant, the Purser and the Captain failed to see the difference, and requested the flight be met by Police. The passenger was taken off the flight, was banned from ever travelling on Air Canada again, and was charged under the Aeronautics Act for interfering with a flight. He was fined $2500 for his trouble. (this was in March of 2010, in Calgary, BTW)
As for vaping in airports, until 2009 you wouldn't get too much hassle in most airports, however the Canadian Airports Council took the position that "vaping" in airports gave the wrong perception to other passengers and would not be tolerated. You will usually just be told sternly not to do that in public view, however I have seen people "talk" themselves into a trip to the Police office because they wanted to argue their "right" to vape wherever they wanted. Discretion goes a long way; I'd suggest the smart move in an airport ( at least a Canadian airport) is to keep your e-cig in your bag, and pop another piece of Nicorette gum in...WAAY less potential for problems.