Let me scoff with you Tim. While I do see some hardware cross-over in the future (mostly laptops with some touch-screen capabilities), I don't see either the laptop or tablet disappearing in place of a unified solution any time soon. Both hardware sets will continue improve independently and I don't see either usurping the place of the other.
In regards to Windows 8... too much, too soon Microsoft. People won't stop using XP to use 7, so I doubt they are going to make the switch to 8. People will only upgrade when they need to buy new systems and hardware that simply won't function in their current OS.
Excuse me, I need to go back to playing with OS X and iOS. :D