The post focuses on trends in e-ink devices which get better and better screens but are still too expensive for something that still has only one use. The poster concludes that what is needed for e-readers to sell well is an e-ink reader that's priced at less than $200. Adding features doesn't help in a single-function device that's too expensive for most people to buy. Here's a quote that makes sense to me: "Either ebook readers need to go multi function or their prices have to come way down." The new Sony, by the way, goes for $399 retail. I have not seen any definitive price for the new Kindle but the old one is now $359.
Interestingly, their commenters appear familiar with reading books on screens. Some prefer multi-use mini-laptops and some are e-reader fans. So I guess there's no single product that will please everyone—at least not yet.