Three years ago, business guru Peter Drucker called London's financial surge of the 1980s the equivalent of America's Silicon Valley boom of the 1970s. He also predicted its demise. Corporate finance, and its parasitic tail of consultants, analysts and lawyers, would decline. Their huge office blocks would empty. Investment banking alone is now reckoned to have shed 100,000 jobs worldwide in the past two years. These jobs will not return to central London.