[fjtorres]

Access to a library by itself is pretty much meaningless as a social equalizer because the people who would (theoretically) benefit the most from pbook access are also the people who (in reality) most deprecate the value of literacy.
The people who most value libraries and constitute the bulk of the user base are firmly planted in the middle class and value literacy enough that the cost of a reader, by itself, would not be a barrier to adoption.
More than reader price, the biggest obstacles to reader adoption as literacy-promoters are their connectivity requirements (which makes most readers into PC peripherals--and PC adoption has levelled off at 45% of households) and their design focus on recreational reading as their primary mission.

In that aspect, as in so many others, Kindles are both the best and the worst that current tech has to offer.

(Shrug)
It's early in the ebook era.

Once the low hanging fruit of the recreational reading market has been properly addessed, which it hasn't, the survivng vendors and the next wave of aspirants will turn their focus to academia, k-12, and literacy promotion as market extenders.

At that point ebooks will have a shot at addressing the literacy promotion function that libraries, radio, tv, and PCs have all in turn tried to perform and all have fallen short of achieving despite grandiose early promises.
This time it might even work.
But I wouldn't hold my breath.

"You can lead a horse..." and all that.