Our phones make calls, take pictures, play music, play video, play games and, by and large, are a bit shit at them all bar the first one.
What I'd like to see is a phone with a smaller screen and decent battery that can make calls. It also offers it's up-link connection to other devices. No need for multiple SIMs or crap like that. Your camera, laptop, whatever just links to you phone and uses that to get on the Internet.
The phone itself becomes optimised to that job and lasts a lot longer on a single charge. A side effect would be that you could make calls from your tablet, laptop, watch as these could simply access the contact details your phone already store (using CardDAV, say).
No need for proprietary bullshit. Do it all on open standards