* No more new drugs today than 60 years ago * Diversification push as blockbusters stumble * 200,000 jobs could go across the industry * Can biotech and contract research pick up the pieces? LONDON, June 16 (Reuters) - At just 28, Duncan Casey has already been from the university science bench to the world of Big Pharma research and back again. Now working in an Imperial College lab tucked behind London's famous Science Museum, he has no illusions about the prospects for researchers in the pharmaceutical industry. "The unit I used to work in -- GlaxoSmithKline's place in Harlow...