I think it sort of depends which school you're talking about. But in general, since the systems are so different, applications are a bit less dependent on scores. Having said that, most of the north americans in my class had good GPAs and decent MCATs (if they sat the MCAT) - generally you want a range of scores that would be competitive for US or Canadian schools. However, weight on GPA and standardized test scores seems a bit more lenient, there are people here whose scores are a bit subpar (but not by much).
They seem to like research experience. You may have noticed the section in the AB application (unless they've changed it) that asks specifically if you've done any research. At least for Trinity, what they really seem to like are people who've done things a bit off the beaten path and are quite well-rounded. People who've not only done some science/med stuff, but who are really active in extracurriculars - sports, music, etc. They also like people who are worldly.
For instance, there's a guy in my class who sings with the Boston Pops choir nd did medical missions in africa. There's another guy who's a ranked surfer. Several in my class of masters or PhDs in epidemiology / immunology / and other fields. In other years, they have Olympic gold medalists or worlds medalists. They really seem to like diversity but in a unique sort of way, not the typical med student gunner kind of way.
. It's a huge step for a lot of north americans - some people have never left home before for a huge period of time, doing short travels doesn't exactly compare. 
