WS may be greedy when it looks at how “profitable” Aeroplan has become and wants to replicate it.
My guess is that the WS programme will likely be something similar to the Bay’s Rewards, or Diners Club with a link to Air Miles. WS programme holders will earn points by flying WS and may redeem flights on WS or convert to Air Miles to redeem other rewards.
I have found today’s Air Miles to be far less attractive than 3~4 years ago. I have experienced increasing difficulties in booking non-air travel rewards, e.g., hotel and the car rental rewards are simply extremely poor value. I have not tried to book air reward through Air Miles recently but from what I’ve heard second hand from friends and colleagues, it is not easy especially if you’re looking for the special BMO WS Mosaik MC deal. I think the “must stay one Saturday night” restriction is still there.