Sanofi-Aventis CEO Chris Viehbacher is leaving no doubts about his ambitious R&D plans for Genzyme. Anxious to avoid a flight of top scientists, Viehbacher tells the Wall Street Journal that he's offering retention bonuses to keep top hands on board. And he's making a weekly trip to Cambridge, MA to emphasize his sincerity. "If you're in a company that has been independent for years, one of the original biotech companies, and you've just been acquired by a big multinational, you're going to...