[murraypaul]

The Kindle app has been updated to the higher resolution display.
iBooks has, of course.
Although Stanza hasn't been updated, and some of the UI elements look a bit blocky, it displays the book text at the new higher resolution.
Unfortunately Bluefire Reader does not. It must use its own custom text display routines, and the difference is striking.

Here is (roughly) the same text in iBooks and Bluefire.