wow, whitethunder, that was totally uncalled for. However, DDS2012 is partly wrong, some canadian schools don't take the US DAT since there is no carving portion on it. Americans can apply to some Canadian schools though, so yes, it can go both ways.
I live in BC, where my school doesnt have any seats reserved for in province applicants. In addition, there are only 10 D-schools in Canada, but for me, effectively there are only 8 since 2 of them are run entirely in French, which I don't speak fluently. Of those, I can only apply to 5 since I don't meet some unusual prereq requirements. This is probably the case for a fair number of can. students - less than EIGHT possible dental schools. So yes, being able to apply to american schools is nice as a back-up, especially w/so few schools to apply to (compared to your 54? schools). I plan on doing it next year if I don't get in to a canadian school this cycle.
Take a look at the university of toronto. They interviewed people with at least a 3.7, base their interviews solely off the DAT and GPA's (no personal statements or LOR's) and the mean GPA of their accepted class was 3.91. With competitivness like that, a lot of smart, qualified, canadians do look down south. Crude analogy: "you'll never score if you don't shoot. the more you shots you take, the more likely you are to score."
getting into dent school is tough, there's hurdles and obstacles every step of the way. People on both side of the border go through it. Thats cool that youre mad about it, but outwardly bashing canadians doesn't help.