I disagree. OS X already has touch support. All Apple has to do is make a touch-sensitive screen for an MBP and add an emulator window for iOS and you have a hardware unit that runs everything.
iOS was originally cut down for performance reasons. Then large parts were locked for security - especially carrier network - security.
Performance isn't an issue, but carrier security is. And I don't think mobile users are going to be happy about having to download a constant stream of unlabelled Windows updates.
Where Apple went wrong was with iTunes, and especially with the horror show involved in getting information into and out of an iDevice. If you have an independent collection of music and books, it's just too clunky.
I bought an Android Galaxy Tab recently, and not only is the screen better than the screen on any iPad, getting books into it is trivially easy.
Either way, I'm glad Cupertino has competition. There's been more than a whiff of complacency from that part of the world in the last year or so, and I hope this makes Cook and Co sit up and stop taking the high end laptop market for granted.
Although gotta say - I'm still amused to see the MS presentation design following the Apple/Jobs presentation style so closely.
Maybe both companies should just merge? That would be interesting...