Green tea is awesome. It probably has some health benefits.
I would caution my friends here, however, that finding causative factors for health from a food is very very difficult. Typically, these types of studies are correlative. there has been some success isolating a particular nutrient and its effect like vitamin c and scurvy, but green tea is very very complicated. Varieties, number of chemicals contained, growing conditions, how you make it, how you consume it, your own genetics and behaviors etc.
There is a (slowly) growing trend to not label foods as "good" or "bad" but to think of food In context of many things. Sugar is neither "good" nor "bad" as it can contribute to problems as well as save lives. Context is everything.
But yes green tea is awesome!