Kat got quoted in the 'Business Courier' here.
Thinking about some of the things mentioned in comments on that page, I think the challenge before every modern city that seeks to increase the number of professionals living there, is to not only retain the 'loyal' residents - who have stayed in that city for some time already - but also to attract newer residents into making the move.
I think one of the biggest strengths that any city could use are its universities. Universities attract people to a city and I believe that students find it easier to follow their ambition to move to an exciting city than do professionals who mind find moving cities a bigger chore.
However, I can think of many cities that fail to retain the huge and excellent student population they support. It would probably make sense for such cities (like Cardiff, Wales for instance) to offer incentives to businesses to encourage them to set up shop.
On the other hand, I've lived in at least one city where although the business has grown tremendously, its university have not kept pace. Bangalore in India, where much of the offshore IT work is done, is one such example. Of course Bangalore has grown quite quickly over the past decade, but surely, one of the reasons why it is host to so many economic migrants is because it has not realized that much more needs to be invested in its universities.
Interesting issue. And probably one that a lot more thought could be applied to. Hell, we could probably write an Economics paper on this!