Yeah that kind of things sounds great.
Personally, I think that a mix between the (stock) nook launcher and a standard android launcher could be interesting.
For example, a screen with the last opened books (if it is possible) + links to favorite apps or something like that
BTW, there is already a Nook specific launcher (Relaunch
). It has interesting features but I don't use it as I don't really like how it looks ...