I've become something of an expert on the prepaid market. The minutes on my Tracfone don't expire until 2011, and every time I reload the minutes, it pushes the expiry out further. It's really exactly the benefits mentioned in the article.
What I REALLY want is a USB G3 dongle with X gigabytes of transfer that I can top off as needed, on a prepaid plan. I have a few applications where I have no data use at all for 8 weeks at a time, and then I'll need 200 MB a day for 4 days in a row.