Personally, I'd want:
- 4x6" screen, EXPANDABLE to 7x10"
- color screen
- 300dpi minimum
- enough internal memory to hold hundreds of graphic novels, in full color at 300dpi, as well as hundreds of books
- XML-based text system, not proprietary
- wireless web access
- included solar recharger
- hand-winding or pump recharger
- $250 or less
And as a peripheral, I'd want a fast color scanner, to get all those comics and GNs from my collection in there!
(Now you know why I still read e-books on my PDA.)