Sunday morning, and it is all over but for the tendering of shares, according to the news stories. Yes, there is the extrication penalty that AC would have to pay on behalf of Cdn to get out of oneworld, but I wouldn't be surprised if AC joins SABRE in exchange for AA's "poison pill", etc. And I agree, both BA and CX would probably prefer to have their routes across the Atlantic and Pacific respectively to themselves without having to share with Cdn. They will figure out ways to counter the STAR/Aeroplan bias their high-yield passengers will have.
In the meantime, it will be interesting to see if we get SE and Elite renewal cards in February, instead of ExecPlat and Gold ones. I doubt Ottawa will give its approval (formally) in time to affect the FF programs for the start of the new year, so Cdn is likely to be in oneworld through most of the coming year. (Just in case, I've just booked my BA F-class trip to South Africa for August. I still think this is the best FF redemption value in either alliance.)
My big worry now is the number of elites at the top two levels vying for upgrades, etc. out of YYZ particularly. We've all read the "fortress hub" blues of our US compariots have posted (Atlanta, Minneapolis, Chicago, Newark) so by next summer we should prepare ourselves for the worst.
At least the oneworld 100K promo has spurred me to reactivate my old AAdvantage account, which should have a modest 125K in it by the time my five flights are posted, and I use next week's YEG-YYZ flights on Cdn to complete my Gold Challenge. (Some elite tier is better than none...)