I like this. For a few more examples, here's what I'd get if the USB devices around me could be reached from remote web servers:

flickr.com could grab the photos from my camera. Another website could take timelapse photos with my camera and compile them into a movie.

HP.com could check on my printer and run an automatic cleaning when I don't use the printer for several days. I also don't mind them gathering usage info on how often I jam the paper, etc.

Remote monitor my UPS. The power company might care to have my outage data. Or I might use a watchdog site that not only checks my web and mail servers, but also my power load.

I have some USB/1-wire temp sensors on my computer. A large building or server room might want to spread sensors like this over many computers, and then they'll want to be gathering the results in a central place. Your web-usb bridge would reduce the custom software on each node.

Games and other interactive sites could make use of unusual input devices, like the PowerMate or a dance pad.

I can connect my laptop to my cell phone for networking (or use nearby wifi). I have a GPS that is reached via USB (and then bluetooth). While it's nice for the laptop to know its position, I go to some trouble to broadcast it to a mapping website. It would be fine to instead connect the GPS to the mapping site.

I know all these are separate from your original goal (setup the new TV). I'm in favor of your usages too.