I have no immediate plans to fly into Canada, and as has been said, Transport Canada really hasn't decided either when or where ADS-B Out will be required, other than they have decided that it will require the international standard frequency, which is 1090 MHz. "International" also means Mexico (still somewhat in limbo) and other countries. That's why I decided to go with a 1090 MHz system, so that my airplane will be usable in any other country, not just the US, once the ADS-B Out decisions have been made.
There is another benefit to going 1090 MHz, too, within the US. If you're one of those who really likes to fly high with your turbo-charged airplane, 1090 MHz will be required above 18,000'.
In any event, whether a 1090 or 978 system is installed, the biggest benefit for many of us is that with an appropriate ADS-B In receiver receiving on both frequencies, such as a Stratus product, you can get in-cabin weather and traffic. You only get traffic if you're either equipped with ADS-B Out or are flying within the "hockey puck" of an equipped airplane, and until everyone is also equipped with ADS-B Out, not quite all of the traffic will show, but believe me, it's a really amazing benefit. I have had several instances in which I could tell that I was converging on traffic at my altitude but I couldn't see the other airplane out the window. But I changed course or altitude anyway, while the other aircraft barreled on as if I hadn't been there--obviously unaware that I was.
Another thing I've discovered--I can have flight following from ATC at much lower altitudes than before, including flying into the mountains. On my last flight from Greeley to La Garita Ranch, I stayed fully in contact with Denver Center all the way to within 5 miles of La Garita--they lost me as I descended below 1500' AGL. When I left La Garita that weekend, I had only climbed to about 9000', or about 1200' AGL when I called Denver Center for flight following, and they immediately gave me a squawk and said "radar contact X miles north of Alamosa airport". From there I flew to Colorado Springs via Hayden Pass, and I was with ATC the whole way. Anybody who has flown in that area knows that ordinary radar coverage doesn't exist for much of that route.
That's why I think those who claim they're going to avoid installing ADS-B Out at all costs "because I never fly where I'll need it" are cutting off their noses to spite their faces. It's a real safety advantage to have it.
Cary