Better usage statistics and mouse support are all that seem necessary to add
If iOS 7 comes out with some totally new interface that isn't better than the old one, "don't fix something if it ain't broke", staying at iOS 6.
.. and the ability to store files in your own folders, and on that note any file you like. Most of the time I have to store video and documents in Dropbox.
The Video app is a crippled store front on iOS. It's called video yet I can't use it to play video and have to store those in Photos?
Same with documents. Even PDFs of business notes and documents have to be stored in iBooks. Moronic.
The settings app is a bloated unintuitive mess. The text cursor is imprecise and terrible to move (see the many user created alternatives that are better). Safari still fails to work with many Web sites that a regular desktop browser has no issue with, and I'm not talking Flash either. Newsstand store page has no search option (?!) ... and many other instances where it looks stale and static.
Every mobile OS offers dynamic content now yet I'm still looking at the perfect weather in California, the full date can only be seen by opening iCal (how hard would it be to add it to the top bar for consistency on each page, it's been in OSX for a decade!) and access to airplane mode, wifi etc needs to be toggled through the settings menu instead of directly from anywhere.
iOS was revolutionary when it was released 6 years ago but it's one area that Apple has left in 2007. It needs a lot of redesign and not just additional feature bloat and rebranding. They are just riding the brand name hardware wave as long as they can because people will buy it regardless of the UI design stagnation.