The retail will evolve, obviously, just as it does everywhere else. Theatre companies will come and go too, as will the businesses that rent office space there, and the people who live in the condos. I don't think the joint has to be jumpin' 24 hours a day - if it did, the residents would be the first to complain about the Clubland II noise level. King and Bay is enjoyable in a different way on a Sunday afternoon than it is during the week, and that's part of an ebb and flow of city living that's repeated all over town - in traditional low-rise residential neighbourhoods that are busy at weekends but quiet during the week when everyone is at work and the kids are at school, for instance.
Opinions on the Distillery District threads have been clearly expressed, and I think Andrew has made several good points. Some others, who quip that all the buildings should be knocked down and replaced with condo podiums with no public access, clearly even inhale
once in a while, and that's fine too.
adma raises the "campus" model, but I'd go more for the Tuscan hill town one: a destination, different from the surrounding lands, rooted in history, and alive with new life - both residents and visitors. At the creative, conceptual re-think level it's useful to select such analogues ( several of them even ) and take things that already work as inspiration for what the imagination can create in a new development. The other road - alarmist as Andrew describes it - is to try and link this development to other places that are different in order to prove that the Distillery District can't possibly work because it isn't just like them.