Raikes will replace Patty Stonesifer, who was the highest-ranking female executive at Microsoft when she left the company.

Raikes, who turns 50 this month, was recruited by now-Microsoft Chief Executive Steve Ballmer from Apple in 1981. He was Microsoft employee No. 105, as best he can recall. He rose through the ranks to lead the huge Microsoft Business Division, which produces the Office group of products. In the company's 2007 fiscal year, MBD brought in $16.4 billion in revenue, 32 percent of the company's total, and had $10.7 billion in operating profits.

In January, Raikes announced his plans to retire from Microsoft after 27 years with the company. He had been seen as a possible candidate to succeed Ballmer as CEO, but told me at the time he did not aspire to the top job.

"I don't have CEO envy," he said. "I like the kind of role that I play in the business." Raikes also said Ballmer has "made it clear that he wants to be CEO here for many, many years -- maybe 10 years or more -- and I think that's great."

It's not surprising to see Raikes taking one of the highest profile positions in philanthropy. He and his wife, Tricia, chaired the 2006-2007 fundraising campaign for United Way of King County. Their family foundation had more than $112 million in assets at the end of 2005, according to tax records.

And when I asked him about his post-Microsoft plans in January, he mentioned several "passions" that overlap with the work of the Gates Foundation: teaching, community service and philanthropy and agribusiness.

Here is a comprehensive 1998 Seattle Times profile on Raikes. This is his Microsoft bio.