In case you haven't read it already, here's Nicholson Baker's semi-takedown of the Kindle 2 in the New Yorker.
I found that many of his criticisms were no more than esoteric nitpicking (few people get in a snit about fonts), and the epic snobbery that only New Yorker writers can truly effect ([P]ost-Gutenbergian revalorization? GMAFB!). Also, he never touches on what's to come. He comes across like one of those old curmudgeons who used to kick the wheels of horseless carriages, and spit out of the sides of their mouths, saying "ain't nothing special."
Although, I will agree that books look nicer on an iPod, with the added benefit of being able to read at night, while listening to music, and being able to check your email...
Then again, maybe that defeats the purpose.
But as for the Kindle, time will tell, or the Apple Tablet (Tapplet) will.