Trump's chances are very real. This blog tends to be the most accurate predictor of the race:
http://fivethirtyeight.com/
This time last election, Romney had a paltry 10% chance at winning. Trump has made huge gains, with most betting markets placing him between 1 in 3 to 1 in 4 chance of winning.
That said, US elections are always a spectacle. It is a giant hype machine that means very little. I would actually say the US Presidential election means even less than the Canadian election, because in order for any law to be passed in the USA, it needs a majority of Congress to vote for it, and each Congress person can operate completely independently from their party. Each representative in the American Congress has autonomy to vote however they feel like, there is no concept of "free vote" - every vote is a "free vote".
No matter who wins in the USA, it will be business as usual. Just sit back and enjoy the show.