I wanted to suggest a few features that I believe could be significant in the mobile (web) space:
* Adding “force” and/or “radius” support to touch events. I believe this was already in the W3C specification at one point. Being able to detect the intensity or force of a touch event opens up entirely new possibilities of touch interaction. Developers could explore many new paradigms for user interaction with this extra information. Let’s not abandon this.
* Touch hover events. Yes, hovering my finger over the touch screen should trigger hover events. I know you are thinking that a touch screen that can’t detect your finger until you touch it. But come on, capacitance can be detected in objects without actual contact by simply moving to a sufficiently high frequency. Inductance at distance is a pretty basic electrical principle. Surely a touch screen could be engineered to detect finger hovering.
* Apps should be able to register as a MIME type handler with the browser so the browser can negotiate MIME types and trigger an application directly in response to links that an application can handle. For example, my Twitter application should register application/vnd.tweet. The browser should then add application/vnd.tweet to the Accept header, and if a server returns an application/vnd.tweet response (as twitter.com should do if application/vnd.tweet is in the Accept header), it should be handled by my Twitter application.
* Detachable/replaceable camera lens (not actually about web technology, just mobile devices). I want to be able to detach my phone’s camera lens and attach a real camera lens. I don’t need an SLR level lens, just one of the low-end lenses like on a typical $100-$200 camera. The 8PM CCD one my phone is more than capable of capturing a good image if it had a decent lens on it, something bigger than you can fit on a phone. I just want to be able to carry an replacement lens if I am know I am going to take picture, and be able to snap it on as needed. It is fine if I have to manually focus it.