Sprint is already expanding their 4 g network and for $50 a month you can get 20mb/s down adn 5mb/s up with unlimited data . I know some who are using this already . Service will ramp up quickly and it will be the same for at&t and verizon who go to lte verisons of 4g instead of wimax.
Looking at 3g and what it can do is silly , it was created for dumb phones and few smart phones who's main task was busniess not fun and games.
I should have been far more specific.
My purpose with the 3G coverage was not to imply people would use 3G coverage with a download service. Instead, it was to point out how the roll out of a "new" technology in interent distribution tends to go.
My point is simple. Providers like Sprint, Verizon, and AT&T with their "new" networks target the major markets first. That is because those markets cover around 80% of the population of the US. Those markets also only cover ~10% of the physical country. So it is fairly inexpensive to do these type of upgrades.
On the other hand, there are 2 problems with this. First, these areas are densly packed so tend to run into bottlenecks very quickly because it is very difficult to install capacity able to meet demand while still keeping costs reasonable. Remember, most of the current networks are wasted except at peak usage times. Then they are bottleknecked. If you build up enough that you get no bottleknecks at peak usage times, then you have a lot of capacity that is just not used for the majority of your time. Good for the consumer, bad for the company installing it.
Second, the areas away from these major markets are very slow to get new technologies. Often when they do get it, they get an inferior version. I live just 10 miles from one of those major markets. My DSL did not break 640k until one year ago, and it still averages only 1.5Mb. While you may consider that anecdotal evidence, I worked for a backbone provider and can tell you that it is actually fairly standard. Installing high speed internet lines requires either laying fiber optic cable which is quite costly or replacing almost the entire phone system to get rid of things like analog switches. I cannot put it more simply than there is no profit for large telecom companies to install lines in places other than their main markets.
So that leaves government grants and installation programs to make up the difference. Ever wondered what the required speed is to call yourself broadband? The new program going into affect is only 768 kb (
source).
If you want an example of all of that, you can look at the AT&T and Verizon situation I described earlier. It is a very public example which is why I used it.