Ray Ozzie is in. Bill Gates is heading out (but not entirely). And Steve Ballmer is staying right where he is (at least for now). What does this game of musical chairs among the members of Microsoft’s high command portend for the world’s biggest software company? Far from being a source of confusion and uncertainty, Gates’ recently announced decision that he will relinquish his full-time, day-to-day involvement in the company in July 2008 may be just the breath of fresh air needed for a firm facing major challenges to its core business, according to Wharton experts. Gates, in choosing Ozzie to replace him as chief software architect in 2008, has made a brilliant choice, they say. And while Ozzie and Ballmer bring different histories to their roles — Ozzie is a relative newcomer to Microsoft, while Ballmer is a longtime friend of Bill’s and a Microsoft veteran — there is every reason for them to do all they can to work well together.…