Hear me out...
While they're both niche interests I'm guessing there are probably as many people reading ebooks as there are playing emulated videogames. If you check out
http://www.teleread.org/blog/ you'll find a substantial community of people looking for the perfect ebook reader. If you can include an ebook reader with a long battery life, that allows annotations, has a built in dictionary, and reads a variety of ebook standards it ticks most of the boxes they're looking for. Going against you is the size of the screen but the Palm TX is another favoured ebook reader so it's not the end of the world.
Since you're going with linux perhaps you could port Fbreader to it.
Anyway, just saying.
What's the use of an "eBook" reader? I never fully understood the appeal of this, can someone enlighten me as to why i'd want to use an eBook reader?