Sorry to revive an old thread. We are travelling from Canada on WestJet and staying at Pop in December too! Though if it makes any difference we are British living in Canada as Permanent Residents.
I've just read the FAQs on Disney's official site regarding this
FAQ | Complimentary Airport Service | Walt Disney World Resort and it says international guest (which would include us) need to pick up there luggage and then give it to the Cast Member at the Disney Welcome Centre. I really don't want to wait all night for my luggage (I get paraniod about stuff like that, and won't be able to relax until I have it). Disney's site says nothing about being able to keep you're baggage and asking the ME driver to store it under the bus and collect it immediately when get to the resort - Can I still do that? I'm assuming Disney don't mention it because it's better for them to transport it the same way as the rest, but could be wrong.