Superdawg, AC's CRJ's at YYC? Or are you talking about Skywest/Delta?
Anyways, into the discussion. A couple of points on the RJ issue.
First of all, on the CRJ's. All in all I think Bombardier will offer a good enough deal for AC's regionals to buy CRJ's, the threat being that AC would simply buy more mainliners or continue to fly the not-all-that-old Dash8's for longer if the deal isn't sweet enough. I can't see them going from AC. The reason being that passengers prefer them, and it allows AC to compete better with aircraft like WestJet's 737's into smaller cities, like Thunder Bay or Regina or on transborder hops. Simply put, passengers have become so sold on jets since the short hop jets like the DC9's and 737's came out in the '60's that I'm not sure they'd go for props, even though I think they'd be pleasantly surprised with the Dash8Q's. I also can't see them transferring to the regionals. The reason being I'm not sure the pilots union would allow it. There is also, I believe, at this time a scope clause with the pilots that says the AC regionals cannot get more RJ's than the 146's in service, but I do expect that to be removed, and for the regionals to get RJ's. Indications from the management of the merged AC regionals indicates that will happen. The reason, by the way, that AC got the CRJ's in the first place was for transborder operations, where they felt the AC name would be better recognized than AirOntario or AirBC or AirNova.
As far as the Fairchild 728's. Canadian Regional is to be merged with AC's regionals if it isn't sold in the next 2 months, so I rather doubt they will get 728's. I predict AC's mainline aircraft will operate at least during peak hours on routes where they need business class, and Canadian Regional's presence on mainline routes will disappear. And that's not all a bad thing, as I think Canadian Regional when merged in with the AC regionals will be very good at their short hop connector routes, but I'd rather mainline aircraft on the mainline routes.
Now, as far as the ERJ's. I rather doubt it. The only reason I could see that would be for the 35 seaters, but I kind of think they'd just extend the life of the current Dash8 fleet for that.
Which brings me to the Dash8's. I would love to see Q series aircraft. They would be great for short hops like YYJ-YVR, or for any number of airports where STOL is a big plus, especially in the BC interior. The Q100 could be a nice complement for the CRJ's in terms of size. I don't see them really going for Q400's, though, as I think as long as they're going for 70 seats they'd start to want a business class of a larger aircraft.
Which brings me to the AvroRJ/BAe146 jets. I have to wonder what will happen there. They are comfortable, quiet, spacious, and have business class cabins. However, they do have 4 engines, smaller overhead bins, and lack the audio and video of larger aircraft. For these reasons I don't think we'll see new orders for Avro's, but I would't mind seeing (though it is improbable) AC's regionals acquiring a few additional used 146's to tide the fleet over in the short term. Perhaps it would be possible if they are waiting for BRJ-X series aircraft?
As far as 717's, I don't know. I think AC will at least give it serious though. If the price is right, the delivery schedule should be favourable. And I think they're quite well suited for flights on AC's routes of under 1000 miles. But if Boeing doesn't give them an offer they couldn't refuse, well, I wouldn't count on it...
Also, Flying-tiger, I think you can call Inter-Canadien's order for ERJ's dead. The investment fund which was looking at restarting them has pulled out, and there's nobody else looking to invest. I think it's pretty much final that they're shut down for good, even the employees have given up on a re-starting of operations.