One interesting thing to note from that chart is their Beta (a measure of link to market volatility) is less than 1, which is very low for a high tech stock. It basically means that the market views them as less volatile to market conditions than an index fund. Or put another way, more like a utility than a high tech firm.
What does this mean for Microsoft? I think an awful lot will depend on his replacement. I don't think they can get Gates to do another round. Who has the breadth of skills to manage it all? Seems like a complex enough beast that finding an appropriate outsider would be difficult too.
Going to another source [2] I see:
“As a member of the succession planning committee, I’ll work closely with the other members of the board to identify a great new CEO,” said Gates. “We’re fortunate to have Steve in his role until the new CEO assumes these duties.”
This suggests that he could be gone much sooner if the search goes well. These things don't happen overnight, but it could be by the end of the year or even sooner.
[1] http://finance.yahoo.com/q;_ylt=AsQ2vnc2OVs8WNqk.WdDwM.iuYdG...
[2] http://blogs.wsj.com/moneybeat/2013/08/23/microsoft-ceo-stev...