The increased processing power of phones will eventually allow many people to replace their PCs with a phone dock. This massive shift of behaviour will have other consequences in how we use our phones. Besides gaming and graphics, the latent processing power when mobile will be used for machine learning and computer vision purposes. These two technologies allow us to harness some incredible power from our devices even with limited inputs.
Imagine having a fully searchable and indexed transcript of your interlingual phone calls available in realtime, and those words are added to your keyboard prediction that is synced with your account. After just getting off a phonecall with your japanese boss about the board of Newmark Industries, you could sit down at a desk and write a document with correct spellings of each board member's names (you are prompted if you would like them added to your contacts). Your phone finds a route to their head office in the background and tells you which specific route to drive there based on historic traffic combined with current traffic (both foot and vehicular traffic, of course).
The sensing capabilities of phones are getting better and better. GPS is getting more accurate and lower powered. Weather prediction is improving due to remote sensing of cellphone barometers. Machine learning and computer vision techniques are improving for augmentation, prediction, and more.
Phones are a big deal. They are the only technological device (besides glasses and watches) that we carry everywhere. Maybe flexible displays will allow us to have phones without the physical limitations that you describe.