After reading the Gizmodo article mentioned above, I've got a couple of observations.

The ppi rating for the screen is very important as it determines the size of the space around the individual pixels. The more space the worse the eyestrain if all other factors are equal. So even though Apple should improve their text rendering software, there is only so much improvement they can do with a 132ppi screen.

The iPad uses a 9.7" diagonal screen with a 4:3 ratio, and it has 132ppi for a resolution of 1024px x 768px which is about 0.8MP. The nookcolor clearly has a better text reading screen and uses 169ppi. The Retina display is extremely nice, but I agree that the 326ppi is overkill. I would say that 200ppi is more than adequate to create a really terrific screen for reading text. So if you do the math, if Apple kept the screen size and ratio as it is now in the iPad, then a 1600px x 1200px screen would have about 206ppi and a total resolution of almost 2MP. That would kill any other tablet's screen. I have no idea if Apple could find a supplier for 1600px x 1200px screens that use a 4:3 ratio and have a 10" diagonal. I suspect not, and if so, that would raise the cost per iPad. But it would be a screen by which to measure all other tablets!

A far as that goes, even if they used 186ppi in the same sized screen that would be 1440px x 1080px with a total resolution of 1.5MP. That would probably be more feasible, would still allow 1080i and perhaps 1080p, and would still beat all other tablet screens.