Microsoft's new CEO, Satya Nadella, had better hit the ground running with a plan for his first three months on the job, corporate strategy and branding experts said today. "Nadella would be very smart to organize a 100-day plan. That would be brilliant," said Randy Ottinger, an executive vice president with Kotter International, a Cambridge Mass. consultancy that specializes in leadership change and setting corporate strategy. "No question that there's a first 100 days for a new CEO."