Another reason for Net Neutrality is that a lot of ISPs are now throttling filesharing traffic, such as BitTorrent. Rogers does this in Canada, and I'm sure others do too.

What's interesting is that the latest report shows HTTP traffic overtaking P2P as the major bandwidth hog, mainly due to YouTube. Someone's going to develop and make mainstream a P2P over HTTP filesharing protocol, and then it'll be ungovernable.