When the original MacBook Air was released, the same thing was essentially said--that they were non-upgradeable by the end user. My wife had the original MBA, and I was able to upgrade her tiny 80 GB spinning drive with a 120 GB SSD.
The SSD cards on the current MacBook Airs can be replaced with third party (and faster) SSDs from OtherWorld Computing. I was at the point that I either needed to do that or just get a new Mac, and I opted for the latter option.
The retina display MacBook Pro that I ordered should arrive tomorrow. As in the Wired article you referenced above, they too are being called "un-upgradable." However, from what I've read, the SSD cards are not glued in--they just have a proprietary form factor. That would seem to indicate that there's at least a potential for hard drive upgrades down the road if a company thought it would be worth the investment to create replacements. Regardless, I went ahead and ordered mine with the 768 GB SSD, which is the largest that Apple currently offers.
Realistically though, the average person never upgrades their computer. You and I may have, but most people just go out and buy a new computer when their old one starts to get slow or if they run out of room. While it's nice to have an upgradeable computer, for Apple (or any other company) to make them available, they have to use mostly off-the-shelf parts. The inside of the new retina display MBPs are custom designed, which allowed Apple to do things they wouldn't have been able to do otherwise
. I think that's a pretty good tradeoff.
If I can keep my new rMPB for five years or so, I imagine it will be the last traditional computer I'll ever buy. I say that because by 2017, I'm sure there will be some hybrid device that is inbetween an iPad and a Mac. I think the technology that we've essentially been accustomed to over the last two or three decades is about to significantly change.
Edited by R. Mansfield, 02 August 2012 - 11:44 AM.