What happens when he retires or dies?
My thought as well. I'm enjoying the likelihood that we're now at peak Linux, when everything just works, and works well. I can't begin to list the number of wonderful software packages - or hardware for that matter - that were wonderful and useful, but which wound up becoming great, lumbering blobs of useless code, or worse were bought, ruined, and then abandoned by the likes of Microsoft or Google.
Regardless of Linus' reputation in terms of people skills, it seems that he's managed to keep the product moving forward, improving, and stable. Microsoft should be so lucky.