Do we have any Osheaga veterans on the board that can give us some info? I'm wondering how many stages.
I've been going to Osheaga since 2010 and what I can tell you is that it's a pretty small festival (compared to the likes of Glastonbury, maybe even Lolla) and there probably 5 or 6 different stages. There are two main stages which host the headliners, and are located right next to each other. The good thing about this that i've noticed is that only one of the two main stages is used at a time, so you don't have to worry about any major clashes. (Example: MGMT may play main stage 1 while The Black Keys prepare their set up over on main stage 2) and so forth.
Osheaga itself is located on Park Jean-Drapeau, a beautiful island in Eastern Montreal and has a lot of scenery. The festival never usually sells out since it takes place on this huge island, so you shouldn't have to worry about that. Food and alcohol can be a little pricy, but I guess it's pretty similar at other festivals. They do give out free underwear though, so that's pretty cool. But yeah, it's a really nice, tiny festival combining an impressing roster of musicians with local talent while retaining the comforts of being able to breath and not down someone's neck. There is no camping due to governmental laws, but that's okay with me.
My guess is that MGMT will play one of the main stages, perhaps around sundown judging from their place on the lineup poster, but don't be surprised if they play a smaller stage. Devo played one of the smallest stages at the festival in 2010. Hope this helps, and I hope to see some of you there