I'm bumping this ancient thread because I don't want to fully explain net neutrality if I don't have to.
Comcast takes the first shot.
I know this may be confusing but I really want everyone to think about this. Have a look at savetheinternet.com . It's really a scary prospect - the internet could become just like cable, with providers choosing what you can and can't see, how much each "package" costs ("Honey, if we get Package III for an extra 7 bucks a month we can get an extra 10 megs per second, plus access to both Digg.com AND imdb!").
If you have Comcast, please write them an email, send a real letter, make a phone call, cause some ruckus. I'm going to write them a letter myself even though I don't have their services. If we're not on the ball they could slay the golden goose right in front of our eyes.