I want to point out one thing, this article says that tea also has a lot of caffeine. It is true that tea contains caffeine, but it has much less than coffee. Even strong tea tends to contain less caffeine than weaker coffee, there is little overlap. Also, the article seems to imply that black tea has more caffeine than other types of tea; this is not necessarily true. There is no global rule about black, green, or white teas containing more or less coffee. If you want some solidly researched information, I maintain a page on the caffeine content of different teas, and I am careful to cite actual studies to back up all the information there.
Switching from coffee to tea can be a very good way to cut down your caffeine intake. Tea is not only lower in caffeine, but easier on the stomach as well. You can still be dependent or addicted to the caffeine in tea, but it's a lot harder to get up to the unhealthily-high doses of caffeine you get when drinking multiple cups of very strong coffee. I have a page about switching from coffee to tea which discusses the relative benefits, as well as giving some advice about teas to start with if you are a die-hard coffee lover.
I hope this helps! I do appreciate this article, I just wanted to clarify a few of the points about caffeine and tea so that people don't come out with misleading ideas. Tea does have caffeine, but it has a lot less than coffee.