Most of my wishes are matters of software. (I "miss" the pages other ereaders show instead of locations/ I often wish I had a simple text notepad; and I'd love to be able to "bookmark" a whole book or document, so we can jump to it from within another book. Library support would be nice, too.)
The only hardware change I wish for all the time is a simple switch for TTS. I usually need it most when I'm not feeling well and wake up and want it to read to me.
It would be wonderful to just flip a switch to turn it on, instead of navigating the dialog or finding and pressing those 2 tiny keys when I'm shaky and it's dark.
That's probably not big on most lists, but it would really make my day.