Larger display
HD display
SD card slot
That's a start
Not everyone wants a wider display. I would've skipped iPhone 5 and 5s. =P
I find anything wider than the RAZR M hard to use. Either too small or too big.
HD display, you'd either have to squeeze more pixels in the current dimensions or increase width. Squeezing more pixels would be pointless investment, for now. And 326ppi is far more pixels than your eyes can decipher. So what difference would it make if they squeezed more pixels?
Plus, think about this..if you watch a lot of movies on your iPhone, you'll probably-maybe buy an iPad. More money for Apple, and which company doesn't like selling its products and earning some money? Every company in the world.
SD slot will never come to an iOS device unless Apple releases their own storage drives, which will be costlier (or end up making the base more smaller) than the $100 bucks you spend for the next level of disk space. Mainly because, as Gecotech said:
"1) Speed of external storage is much slower
2) File system - Apple would have to update their file system to mount external storage (I'm not an expert on this but think I read it somewhere long ago)"
Although, one thing I am disappointed at is the fact that the camera remained the same. Was hoping for a 10MP. But glad they updated the front facing one.
EDIT: And a higher capacity, with 128GB being the highest. =/