well some people may choose to use their phones via wi fi for internet and data. For 30 a month u can get cable and not be limited. Some people are ditching their regular connection for broadband in favor of the phones data.
Just think if comcast started a plan like att people would drop them left and right
Comcast also has a limit on it, it's just a lot higher. Landline data is signifigantly cheaper to provide than wireless data is.
I use my phone mainly over Wifi Now as well because I have Fios at my apartment. It's faster internet, and my house hates towers, so it's also a lot easier on my battery life.
That being said, I still consume more than 2gb of phone data in a month so I'm a very heavy user. Tiered data WILL affect me. But it's because cell data is getting so fast/stable that caps are inevitable. Unlimited is a nice word, but it's not practical when you're talking Data because unlike minutes or even text messaging where there is a known limit to how much you can use (and only a small minority get anwhere near that). With Data, your ability to consume goes up exponentially with the speeds you get and with the capability of the device.
Droid's caused Verizon's average data usage per smartphone user to triple in a year, they now use more data per device than the iphone, and the Droidx consumes 5x more data on average than any other phone in Verizon's lineup.
What is data going to look like once things like slingbox are feasible on devices that support 1080p playback? Heck, can you even remember how much data on phones sucked just five years ago? Most of what we have today wasn't even considered. What will happen when 4g is the norm?
Data caps don't have to be evil. They still could be, but I'm going to give them the benefit of a doubt with it. If they do it right, this could be a boon for almost everyone, and only the people illegally tethering 24/7 would be the ones grumbling.