Web developers already have a problem making web sites that handle touch and mouse input together. The reason Touch Events support is only on Windows Phone and not in Windows 8.1 is that the IE team found that if they turned on Touch Events in the desktop browser, your mouse or trackpad would stop working on "around 10% of top sites."
That's because those web developers assumed you would never have touch and a mouse at the same time — but nearly all new Windows notebooks today have both. Pen and voice and gesture control aren't common yet, but we already have the Surface Pro and Galaxy Note phones and Adobe's Ink pen and the Jot pen for iPad, Cortana, Xbox Kinect, Siri and Myo (not to mention a Honeywell thermostat you can talk to, to turn up the heating).
The PC isn't growing much but it isn't dying off either. The future doesn't only look like touch — unless you're Google and all you see is Android. It would be nice if the web was ready for that future, and Google isn't helping.
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