Ok, still no clear, definitive answers, so I went on and took a little action. The WHATWG would probably have an answer for me, so I decided to contact someone there. Didn’t really know who it had to be, but fellow Dutchman Anne van Kesteren usually seems to know the Web’s future pretty well – plus, he provides an e-mail address.
Translating his response probably won’t do any good, so in short: there are some rough ideas on how to make it all work, but there’s nothing tangible at the moment. The Device APIs and Policy Working Group is supposed to continue work on this.
Reading through their page makes me realize something else too – why only webcam access? If Google intends to move the OS to the browser, we’ll need more than just webcams. Why not manage your iPod through a webapp too? Anything should be possible. I guess a whole new concept of ‘trusted website’ will have to evolve if functionality like this would come available, but well, there’s a solution to pretty much anything, isn’t there? 😉