I always have to take any new health study with a shovel of salt.  In this article from the Examiner.com they say that a new study found that drinking tea may slim your waistline, but it is not conclusive and a bit misleading. After saying that tea reduces your waistline, they state:

When it comes to coffee and tea drinking, the use of sugar vs. artificial sweeteners seems to play a role in abdominal obesity. And the findings might surprise you. For men, the use of sugar in tea was associated with a nearly 1-inch smaller waist measurement, but the use of artificial sweeteners was linked to a nearly 2-inch larger waistline. Among women, the use of milk in tea was associated with a two-thirds-of-an-inch smaller waistline. But women who used artificial sweeteners had an average of nearly an inch larger waistline.

This seems to be more of a study on the effects of artificial sweeteners than it is of tea. And if it were true, I would not have a nice belly given that I put milk and sugar in my tea.

Yes, tea is good for you, but it is not going to replace exercise and eating right.