I've been thinking about this lately, it always amazes me how much lighter and sleeker the reader feels when you have it in your hand without the (standard) cover attached. While I pop it out once in a while, I really would prefer a hard 'slide-out' case there you can stash the reader for transport, yet easily pop it out for reading (preferably with a cool mechanism).
While thinking about this, I tried to mentally sort the requirements and wishes I have for a case.
Requirements:
1. Protection
a. Protection from impact
b. Protection from crushing/screen 'denting'
2. Ease of use - no fiddling when inserting/removing the book
Wishes:
1. integrated reading light without compromising on size and bulk
2. memory card storage
3. integrated bookstand
4. book-like appearance?
Here's an early concept, based on the
hollow book idea. To attach the reader, I would say velcro. I call it the frankenbook.

IT'S ALIVE! ALIIIIIIVE! (also, a testament to what a hack I am with
GIMP)
So, um, what would you want in a cover/case? How about a solar panel for self-charging?