I also got the offer, based on the Aeroplan Platinum card. I also have the gold Amex, but so far, no promo code e-mail tied to that one. It would be nice to use it twice. The promotion has a nice booking window, allowing until Sept 30 to book and travel to Dec 15--long enough that I might want to book two vacations.
I already booked an October trip last night, which fortunately was still within the 24 hour window to cancel, so I have rebooked using the discount.