What is net neutrality?
You can read details here, on Wikipedia. In a
nutshell,
Network Neutrality — or "Net Neutrality" for short — is the guiding principle that preserves the free and open Internet.
Net Neutrality ensures that all users can access the content or run the applications and devices of their choice. With Net Neutrality, the network's only job is to move data — not choose which data to privilege with higher quality service.
Net Neutrality is the reason why the Internet has driven economic innovation, democratic participation, and free speech online. It's why the Internet has become an unrivaled environment for open communications, civic involvement and free speech.
Breaching network neutrality affects everyone - corporations, small business owners, students - everyone using the Internet. The internet has turned into a innovative medium for communicating to people. All was well till now, cause the telecommunication industry was doing its job - transferring bits from point A to point B. And it has done that job well.
However, now the telecommunications industry is trying to dictate what content the user can access. How you ask?
For example, say you want to use your favorite service A. Your ISP offers/has a financial incentive from service B. Guess which service your ISP would route you through?
As predicted by Eben Moglen, the fight with the telecommunications industry has begun.
Take initiative: Act now,

Update: I did some more reading online. AT & T’s Ed Whitacre wants consumers and content providers to pay for use of his network. “The Internet can’t be free … for a Google or Yahoo or Vonage or anybody to expect to use these pipes free is nuts.”
Reply: The reason the telecommunications industry exists is because the content providers exist. and vice versa. Net Neutrality is the reason why both are able to exist, in a symbiotic relationship. Breaking network neutrality will have disastrous consequences to us, the end users.