The GQ rating could be made to work possibly by making it a more complicated formula based on connection speed, and number of files downloaded/shared. Modem users might get a class/rating of their own (say muGQ) and be exempt, while cable users or aothe broadband users could all be rated on the same level.

Also, it would be hacked and tinkered with within days of its release, and that could not be helped. Clients could be made wich would give out 100% GQ ratings all the time, as well as report being a different client (so you wouldn't know of these false ratings). So the GQ system is mostly plausible as a good faith / honor system / voluntary system. But, the only people who would cheat it are malicious broadband users, and why!?

Just my thoughts.