Unfortunately, my theory on this is Steve is worried he won't live long, that his pancreatic cancer will come back. If I was in his shoes, I wouldn't want to be sitting on cool projects due out in 6 months if I might not be around to show them as the proud dad when they're born. His famous commencement speech shows he's worried he won't be around long.
He should be very proud of his accomplishments. He and Woz have truly changed the world for the better, and Jobs has done it several times over. Apple II, Macintosh (or Lisa if you prefer), iPod, and now iPhone, and who knows what else is cooking in there. He deserves to have a chance to show off.
And if anyone reading is pro-Microsoft, the Mac is the reason Windows has worked so well. Excel, Word, and the mouse/graphical interface were all made practical by Jobs. Not invented, made practical. Every thing he's done involves prior art mind you, and that does not diminish his accomplishments by any means. In fact, I believe it is a kind of genius, a different kind from the one that invents - he takes inventions and makes them incredibly usable. I sort of specialize in working on translating medical research into clinically practical treatments, so I empathize with the idea that a great invention might languish, or might be used but in a crude or half-assed way, or that it might be implemented so that it is easy to use, practical, and gets a lot done that couldn't have been done using the old methods. That's what Jobs does.
After all, Edison didn't invent the light bulb. He invented a kind of light bulb that was practical and that lit the world.