Part of the problem with network neutrality is the telecommunications companies don't have the bandwidth for today's demand. This is entirely their fault for not upgrading the infrastructure despite $200 billion in increased rates and tax breaks to do so.
Normally competition will force these companies to provide better service at reduced costs. However with the broadband oligopoly we currently have, there is no competition to provide the incentive. As a result, the US broadband ranking is slipping worldwide. In the 1990's the US was the world leader in broadband access. According to The Information Technology & Innovation Foundation, in 2008, the US has dropped to 15th in the world.
This only hurts innovation and the US's ability to compete world wide. Since there doesn't seem to be competition, enforcing network neutrality is one way to force the telecommunication companies to upgrade the infrastructure. Once the infrastructure can handle the demand, the telecommunication companies will have less of a need to impose limitations on Internet access.