It would be nice to have some of the features of having an item in your library without have to copy the file to internal storage. The main feature I want is to view a TOC on the LCD side. Only way to do this is add the file to the library.

It would be nice for enTourage to post what they are working on. That doesn't mean it will be in the next release but at least people can see what is coming.

Others already mentioned:
Landscape mode on e-ink
Better Power Management
Font Choices