Here's an excerpt:
Defeating net neutrality would give telecom companies the ability to charge content-providers (like Google, eBay and Amazon) to use their bandwidth and, in essence, have access to their subscribers. Not only would the content providers have access to the telecom subscribers, by paying they would have preferred access -- higher bandwidth and better delivery of their content. At the heart of this strategy is the telecoms' claim that they need revenue to make necessary updates to Internet infrastructure. Emerging technologies and media require improvements, they say, and the money has to come from somewhere.The whole thing's here.
Those in favor of regulation worry that telecoms will abuse their control and punish companies that won't pay up. Catherine Yang of "Business Week" explains that, "The network operators could block consumers from popular sites such as Google, Amazon, or Yahoo! in favor of their own. Or they could degrade delivery of Web pages whose providers don't pay extra. Google's home page, for instance, might load at a creep, while a search engine backed by the network company would zip along."