I was completely unaware of the disappearance of the basic cell phone...
It looks like even Go Phones are mobile internet ready now.
Feature phones are 72% of new handsets sold (in America)
Both articles draw these statistics from an NPD group report on Q2 2009 Mobile Phone Sales.
Obviously, device capability and services being subscribed to are two different things, and at $19.99 for 100 MB of data, a Go Phone is a pricey browser.