Obviously a download from a good server will saturate a 100mbps line, but so what? Other than video games and massive file backups, 25mbit is fairly fast. I pay for faster, but it's only a marginal improvement.
Edit: I meant to add this:
We have the ability to provide (or at least develop) 100mbps connections to the vast majority of Americans, and we recognize that Internet transfers aren't getting any smaller. It's good to look at ways to improve the status quo (e.g., QoS), but we should also be looking to change the status quo itself.
I come at this with the thinking that, it's not "us" that's building out the infrastructure, but the telco companies. So, really what we are doing is analyzing the build-outs telcos are doing, and judging whether it is good enough or not. Is it really fair to say that, if there aren't 3+ telcos providing 100mbps, but there are 3+ providing 15mbps, that's not good enough?
In light of the obscene amount of money that taxpayers have sunk into ISPs, there's no need for that. They may be the ones building the infrastructure, but they're taking advantage of us along the way.