My issue with Verizon & ATT (& eventually Sprint and all the others):
These cellular companies have stated what their expected usage is for a typical customer based on historical data. However, more and more phones coming out are getting new features. I have heard they are working on Netflix Watch Instantly for the phone, as well as premium Hulu services, and other data-intensive video streaming services. (Especially when you consider an out-to-tv connection, steaming Netflix on your phone to your TV doesn't sound so insane when on the road.)
So, now that we are changing from occasional mobile web browsing to full web browsing and video streaming, the typical users usage will skyrocket - right out of their historical usage levels and into serious overages. This is also why they market the web based powers of their phones.
From experience this is what I have learned: streaming 1-2 movies of Netflix for a 5 day vacation (about 3 hours average a day) consumed almost 4 GB of my "unlimited" 5 GB mobile broadband plan.
Their historical trend are out-dated and will lead to very dissatisfied customers. Why advertise the speeds of cable and DSL broadband with 4G service only to say we are going to cap you at a fraction of what a cable company would dare try? The obvious answer is because they know customers will go over and get those famous texting-without-a-plan styled bills (in the $1000s to $10000s of dollars for one month).
If only Sprint would come out and say they weren't going to do this. But they will. They went from unlimited to 5 GB caps, and they eventually moved to canceling you for 2 out of 3 months exceeding usage to the charge per kb over... so they will go to capping their on-phone data.
Oh well, guess I am going back to the most simple phone again with a cheap plan. In other words, they are loosing out on $60 for my tethered smartphone - and the $60 I convinced my wife to spend on getting the same thing. At least that will halve our phone bill.