In what is bound to make Mac users like me a bit uncomfortable, in his interview at the "All Things D" event, Apple CEO Steve Jobs said that the post-PC (that's "personal computer," by the way, not a Windows system) has begun. And I'm sure he feels the iPad is a milestone in this transition.
"PCs are going to be like trucks and are going to be used by fewer and fewer people," Jobs said. "This transition is going to make people uneasy. When you start to enter the post PC era it’s going to make people uncomfortable. We’ve embarked on that. I don't know when it’s going to happen, but the transition has essentially begun."
My take: the personal computer era will never end, though it will change and evolve over time. Sure, more devices such as the iPad will be introduced. For some folks, they will replace the traditional computer. As for the computer itself, as I've said on numerous occasions, I think future Macs will increasingly merge features of the iPhone OS with Mac OS X. That will result in Macs with new form factors. If Jobs considers those to be post-PC devices, so be it. They'll still be personal computers by my definition.
Speaking of which, the post-PC era is defined by the Free Dictionary by Farlex (http://encyclopedia2.thefreedictionary.com/post-PC+era) as the use of numerous machines each dedicated to a specific application in contrast to the general-purpose desktop or laptop computer. By that definition, the iPad isn't a true Post-PC device. Neither is the iPhone or iPod.
For example, you can use the iPad to listen to music, watch videos, read ebooks, surf the web, do word processing, etc. So it's hardly a device dedicated to a specific application. Also, at "All Things D," Jobs said that future incarnations would be better for content creation as the software and hardware evolve. Hmmm. So the iPad is evolving into a mini-PC?
I guess all this depends (sorry to go all Bill Clinton-y) on you on how you define "personal computer." I also have to note that Jobs, as brilliant as he is, has been known to be wrong. He was quoted (and perhaps he didn't actually say this) that the Segway was as "big a deal as the PC" (though he purportedly thought the early design "sucked").
Even using his truck analogy, when you need to do some serious work or some heavy hauling, you're going to need a truck, not a car. Or a Segway.
I think we will see more devices such as the iPad. But it's my outlook that they'll be supplements and complements to the personal computer rather than replacements.
-- Dennis Sellers