The fundamental issue underlying the net neutrality debate is who gets to control the flow of information over the internet.
Google and Lawrence Lessig are two entities in favor of net neutrality. Proponents of net neutrality say it is important because it will keep the internet a neutral environment, so network providers will not be able to give content providers faster or slower service based on how much they pay or their subject matter. This will keep the internet on a level playing field, so the only thing that will determine whether a website will succeed is whether people like it and use it. If net neutrality is discontinued, network providers could greatly slow traffic to and from sites they deem less desirable, or those that are not their clients.
Comcast and AT&T are two entities that oppose net neutrality. Opponents of network neutrality say it impinges upon quality of service: packets of data all must be treated as equal, be they email, streaming video, or an online backgammon game. This means the network providers can make no guarantees as to timeliness of their service: for example, they cannot guarantee packets of streaming video data will all arrive quickly enough to ensure a smooth viewing experience. They believe this will stifle creativity and innovation because people will be less willing to invent applications that demand timely data arrival if they know network providers cannot guarantee this. Also, the infrastructure is quite dated, and it will be up to the network providers to replace it with faster, more technologically-advanced materials; these companies need some way to come up with the money to be able to pay for these improvements.
I am strongly in favor of network neutrality. I do not find the opponents of network neutrality's arguments to be convincing, in large part because a) they seem to already have more than enough money, and can surely afford to make upgrades to infrastructure; and b) it seems suspicious to me that it is the big companies who stand to gain financially that are against network neutrality, while it is the innovative websites and web-based companies (and a law professor from Stanford!) who support network neutrality. I know which side I'd rather be on! Also, I am a huge supporter of www.bmezine.com, a website which has been banned in a number of countries because many people find its content objectionable. I would be extremely perturbed if network neutrality were repealed and the network providers slowed down service to bmezine.com because they found its content objectionable. Content discrimination is not what made our country great! Innovation, and the ability of little guys to take an idea and make it accessible to the rest of the citizenry, even without buckets of money to begin with, is an integral part of our national heritage, and I believe this should be protected at all costs.