By Bill Rigby SEATTLE (Reuters) – As Microsoft Corp prepares to unveil insider Satya Nadella as its new chief executive, investors and analysts are weighing how effective the 22-year veteran will be in re-igniting the companys mobile ambitions and satisfying Wall Streets hunger for cash. The worlds biggest software firm faces a slow erosion of its PC-centric Windows and Office franchises and needs to somehow challenge Apple Inc and Google Inc in the new realm of mobile computing. Most agree that Nadellas background in creating Microsofts Internet-based – or cloud – computing services makes him a safe pair of hands to take the company forward, but there remains a question over his ability to make Microsoft a hit with consumers, or with impatient shareholders. He is the right person to drive safe, right down the middle of the fairway, and continue Microsofts strengths, said Rajeev Chand, managing director and head of research at tech investment bank Rutberg Co. What we dont know is will Nadella help with the consumer revival, or with the mobile revival.