Look and feel-wise...the iOS look is getting dated. I don't think they should parrot the flat square look Microsoft is going for nor the Tron look in Android. But this
http://dribbble.s3.amazonaws.com/users/3331/screenshots/1108...
is getting old (OS X is even worse)
I'm not a visual designer so I'm not sure I'm entirely qualified to offer suggestions, but there are other button styles, even completely new ones that would work.
Some ideas:
How about some variation on the one in the upper right here?
http://www.colourbox.com/preview/2584456-712013-exit-beautif...
VST interfaces are usually choking with ideas
https://www.google.com/search?q=beautiful+buttons&hl=en&...
Or why buttons at all? I should just be able to interact with the direct metaphor of what I want.
Or a pop-up circular button system like in Palantir?
http://www.palantir.com/wp-content/static/techblog/2007/08/s...
The interface looks like candy, instead of trying to outshiny the competition, maybe it should be matte? Then use shiny bits sparingly.
http://remodelista.com/img/sub/uimg/Janet_Images/suga-black-...
etc. etc. etc.
Let's not go for shiny kitsch, let's go for expensive sports car with a matte paint job.
Other than that, cross app communications (intents) and resolution independent layouts as an option would be nice and get Apple out of this weird resolution multiplier lock it seems to be trying to bust out of (with the exception of the iPhone 5).
How about other interface bits? There's a button and the screen, how about capacitive edges that can be used for interface sliders or other things? I love capacitive buttons on Android phones (when they had them).
Or let's get crazy, a completely disappearing product all together. Jam the guts into a watch, and a small wireless earpiece, or maybe ear/eyepiece and voice controls and a capacitive touch panel on the watch, don't make it look gaudy like Google Glass, get top eyewear designers to pump out different headpieces (lots of upsale potential there) etc. etc. and top watch designers to design the handpiece and turn computing into ubiquitous wearable fashion driven computing (with sales cycles as fast as the fashion industry -- seasons) and people will buy 4 sets of devices a year instead of one every two years.