Someone does a similar device in terms of form factor, battery life, screen quality, price etc. and adds stylus support and robust document markup options and I"ll buy it day one!
I agree 100% with the author that tablets are NOT pcs and companies should be wary of making them like PCs. True Tablet PCs have failed for years. I just don't think there's much of a market for tablet PCs running windows, OSX and having all the features etc.--most everyone has a laptop, desktop, netbook (or 2 or 3 of those).
Tablets need to fill a different niche so people don't just say "I can do all that on my PC/laptop" and not buy them. It's a pretty small niche of people who need a laptop with a touch/stylus screen--as the poor sales of tablet laptops have shown.
I feel there's a much larger market for tablets like the iPad that are used more as document readers, document mark up tools, video and other media viewing/listening and not full on computing.