Duke,
Its because of changes just like that, that I always recommend not to go out and blow a whole bunch of money on new systems. Things change too fast with these infernal machines and, soon enough, its obsolete. It will be interesting though to see if that actually takes off. Imagine, your whole computer in a couple of pens!
I saw that article on the HD recently and thought it was interesting but, I wouldn't do it, at least right now. Too many problems.
First, its only a max of 4 Gigs. You can't stick a 2, 4, 6, 8 or 16 Gig chip (as if they make them anyway) in there. Any of us would fill that up in a week or two with all the video thats now available.
Second, the price. $150 for the card sounds OK until you realize that you then have to buy RAM (and lots of it) for it to work. Figure on at least $100 per 1 Gig chip so add another $400 to $450 to the price. $550 to $600 for a HD? Not me anytime soon.
Third, since RAM is volatile, any memory stored in it is usually gone as soon as the computer is turned off. They say in the article that I read that, as long as the computer is plugged in your OK. And if the power goes out you have about 10 hours to get the power back on before the internal battery goes out! Yikes! No where near enough time. Unless you have a UPS and a generator.
Right now, I wouldn't touch that thing with a ten foot pole.