Hard to say...is basketball as big as hockey? Or is it bandwagon fans? It wouldn't be surprising in a way as they are the only NBA team......kind of like the Jays.
I was mildly interested to see Toronto get the Raptors franchise (despite the Jurassic Park gimmicky name), and never followed or watched a game (I personally couldn't care less about basketball), and only tuned in to the last part of the playoffs last year - haven't really payed attention this year either. I won't buy any merchandise because I really don't care.
With the way demographics are changing, the cost of playing entry-level hockey, etc, basketball may be more popular. Now, Hockey still owns the desirable demographic of wealthy males 19-49. But, even that is shifting as kids who grew up primarily basketball fans enter the workforce and grow into senior management positions. A ton of my friends from university who are 2nd generation Canadians, who are somewhat indifferent to hockey, but love Basketball or Soccer are now entering a phase of there lives where they are making good 6 figure salaries and fit in one of the most desired areas for advertisers.
I love hockey, grew up playing it, have followed the Leafs for as long as I can remember. But, it is just not a very inclusive or accessible sport. That was 20 years ago, and even since then costs have risen significantly. It's easy to buy a ball and play at a local park. Hockey to play consistently is a significant investment time (driving from rink to rink mid-week for travel hockey) and money-wise.