CMSWire had a provocative piece the other day suggesting that the PC has basically gone belly up; in it’s place, mobile devices that thrive because of the cloud. Eventually, in my opinion, the distinction of the end node or leaf device that the user interfaces with is becoming more and more irrelevant. What matters is the ubiquity of the data access and the App.
For example, I constantly (using Dropbox) go from my iMac, to my laptop, to my iPad to my iPhone — all working on the same data set. Creating, reading, updating and deleting (managing my data) using a diverse set of edge devices that today have varying levels of capability as noted in the article. I.e., I won’t do content creation on my phone, and only limited updates on iPad. I will, however, do more consumption of data on those devices since it’s convenient.
Back to the ubiquity comment: as those devices become faster (e.g., we see dual-core phones with quad-core android devices emerging, although who knows what the battery life on a quad core is right now), the core UI capabilities will continue to improve. The gap of full content management will close so that the proportion of actions on each of the devices will be about the same. The edge device will not be the issue, but everything will be about the App.
How well the App takes advantage of the compute power and the core UI services (gestures, motion) will make the difference between a good UX and a great UX.