With Air Canada having announced new orders for A340s, A319s, 767s and A321s. 717s and possibly A318s could well be ordered. It's fairly obvious to me which routes most of these aircraft types could be used on. This is mainly because the 717 (or the A318) would replace the F28/737-200 fleet, and the rest are simply more of those types already in service with AC. But the A321 is a bit more difficult for me to imagine which routes it could go on. I don't think AC has had an a/c with a capacity similar to the A321 or the 757, which would be intermediate between the 767-200 and the A320. AC is likely to have about 150-160 seats in the A321 (sorry can't exactly remember).
Might AC's A321s be used mostly on domestic routes such as YYC-YYZ, or will they be used mostly on transborder routes such as YYZ-MIA? It'd be neat to see an A321 in AC colors at an airport in Western Canada like YVR or YYC, if not YEG!