Two things that I think Apple could easily introduce to improve their products – dynamic keyboards and profiles.
Dynamic keyboards – to not take advantage of the fact that the keyboard can show lower case letters is pretty poor. Then again the static keyboard is skeuomorphic in that it stays the same like a physical keyboard and Apple love their skeuomorphic design (until iOS7 if rumours are true). Whatever, it makes no sense and should be replaced by a much better, responsive keyboard.
Profiles – why no profiles on the iPad. These are often communal devices and it would help to separate content based on users such as by age groups in a school setting or by family members at home.
Note, both the above are standard