"A man's got to know his limitations..." Clint said the lines, Mark seems to know they ring true.
He is totally correct about the _applications_ having to be tablet ready, not just the OS. That is something that iPad and Android have natively, as they evolved from mobiles. But Mark is right - Windows and Linux have a much longer road to go to provide applications that are keyed to a multitouch interface.
Once again, I keep rooting for Ubuntu to hit it big with the right applications...and I'll keep my fingers crossed. After all, knowing your weaknesses (and publicly identifying them) is the first step to solving them...