I just had another thought on this: mobile usage does not necessarily imply that the back-end is entirely on the device as well. For example, the app I'm build

I just had another thought on this: mobile usage does not necessarily imply that the back-end is entirely on the device as well. For example, the app I'm building right now has an entirely iOS-based UI, but the brains are hosted on the public Web via API. The app talks to the back-end via Websockets for anything that requires brains. This type of architecture allows your application to participate in the UI-du-jour (native apps) while at the same time participating in the open Web. And you can simply write another client when another type of device (I dunno, Kinect?) becomes the consumer's preferred method of consuming. I think it will become much more popular in the coming years.