Are you staying here for school, if not then definitley a laptop. I lugged my desktop back and forth to school every year for 4 years and it was a huge pain in the ass. Even if you are in Calgary I would still go for the laptop, with all the wireless places all over campus now you almost never need to use a school computer.
I'm heading back to school in september so this time i got a laptop and I LOVE it. I actually read an article on cnet.com a couple weeks ago that was saying laptops are becoming even more upgradable lately. I'll see if I can find the article.
Edit.. So i couldn't find the article but there is tons of good info
Here