I think that most people posting in response to this article that don't seem to "get" it are having difficulty because they are failing to grasp the underlying reason these devices exist. People are throwing around the idea that these devices need to be easy to use specifically for the "masses" that are computer illiterate, and that is simply not the case. As others have mentioned, tablet and portable touchscreen devices have been around for years, but have never caught on. Why? Because regardless of the fact that they are full fledged PC's with the ability to use a huge library of PC software (iTunes, Amazon, whatever), the user experience is so terrible that it makes all but the few diehards turn back to devices with conventional input methods (k/m). The "masses" is obviously not the only demographic that is turned off by this method of user interface.
The author of this article is trying to articulate the possible solutions to this problem, which all revolve around refining the touch based user interface every step of the way, including the end user software that would be used on it. I know that I have absolutely no interest in something with a custom UI that just loads standard windows applications. Sure it might be easier navigating to the program, but the application itself would still be clunky, awkward and inefficient. Touchscreen devices themselves, even the better designed of them like Android and iPhone OS, are still often cumbersome, so the fewest steps to achieve the goal the better whether it be downloading a song, a book, loading an app or playing a game.
Personally, the techie in me yearns for a tablet based on a modern OS with the option of full control and accessibility for media including the ability to install any software I want, connect any external third party device I want, access any media format I want, but with a user experience that is truly different from anything else I currently have access to. And right now that device doesn't exist and ultimately, for me, for this class of device, the user experience is what it is all about. I can do anything I want on my huge, fast, crossfire, overclocked desktop PC or my ultraportable, HD video playing laptop, and have my iPhone for pocket sized mobile computing. If I'm going to drop my $$ on another device category it has to do something different, to make something I already do more enjoyable. As it now the iPad comes closest to doing this, but HP has an opportunity to take all those things I want as a techie and combine it with the user experience I want.