King's Cross - will demand match the opportunities?

I took a look at the development north of London's King's Cross railway station this afternoon. Already years under construction, with parts becoming accessible to the public, its ambition is becoming clearer.
It is the biggest undertaking - offices, shops, restaurants, residential, public spaces, and a university - in central London in 150 years.
Big enough to have its own postal district - N1C - the 8 million square feet project, which gained its main planning consent in 2006, still has a long way to go to completion.
It has a superb location but I wonder if demand will match the opportunities it presents given the gloomy economic climate is unlikely to lighten any time soon.