Right, so they're doing fine now - and they will be doing fine for the near future.

But no product lines last forever - even Windows is bleeding market share, and upgrade rates are dropping like a brick. It seems a lot of people are happy with Win7 (or even WinXP) and not moving.

This strikes me as a Blackberry situation - market leader by a mile, but attempts to modernize and develop the Next Big Thing have all failed. They have enormous momentum and can coast for a long time - but what happens after? RIM failed to react to changing markets due to iPhone/Android, and arrogantly threw around their (momentum-based) sales numbers. Then those dried up.

I think the point was, how many of those billion dollar businesses did he inherit? Doesn't the emergence of, say, SharePoint, show that he didn't just extract money from existing profitable businesses? Microsoft seems to have done pretty well at creating new profitable businesses under his tenure, but they're not the sexy consumer products that people like talking about.