^^ oh i agree.
However, I believe we'll end up with iPads, etc that can pair to OS X style interface devices (they kinda already can) to run OS X style apps - on a big screen via Airplay for example), and the iOS sandboxing, etc is already coming to OS X.
The differences between the two platforms are going to narrow to the point where a single OS will be on both devices, providing both interface styles depending on the input device(s) currently in use.
That's how I see it in any case - for most people, the traditional "laptop" or even "desktop" computer is eventually going to go away, and be replaced by something like an iPad (in terms of form factor, with memory/cpu/gpu performance on steroids) that can be used both on the go, and with desktop style peripherals for doing more intensive work when you return to your desk.
Of course there will always be specialized workloads that require something like a Mac Pro, but the vast majority of users simply don't (and in a few years especially, won't) need the horsepower that a non-tablet device provides.
The real "killer app" for this is going to be that users can just work on the single device, when they leave home/work, simply pick up a tablet (wireless connectivity to mouse/keyboard/trackpad/display/etc - maybe unplug the charger if and inductive charging pad isn't available) and leave with all of their apps/data available on the device.
No need to worry about "do i have app X on this?" to continue working, the UI will simply shift to touch/tablet mode and you'll be able to carry on. Your data will automatically save to either iCloud or the corporate equivalent (future apple corporate "private icloud in a box" product) as required.
Maybe my time estimate is off, but I'm pretty sure this is how things are going to end up in the near future. Just as the laptop is killing the desktop, and the desktop killed dumb terminals hanging off a mainframe, the tablet will kill the laptop... it's just a matter of time.
