Well first I'd like to emphasize the "there's a difference between tights and leggings" arguement.
That said, "high fashion"-wise leggings are just about played out. They've hit the streets strongly and have gotten used and abused in all kinds of manners. Regular, day to day wear, I believe they are still going quite strong. I don't attribute this to celebrities or magazines, but to the fact that they still hold their own charm and merit to some people. And while, I would personally never even so much as touch the things even while they were so popular and touted, I think they can still be worn.
Overall, I think it represents an interesting shift in ideals as people start to get away from revealing clothing, like the sudden surge of empire waists, trapeze tops, and peacoats as less stopped being more, and "more" became more again.
In any case, I'd say they are in style. Yet they will always have naysayers as they did even in their peak days. Overall, fashion is about personal expression and flair, so if you think they look good, ROCK ON girl!
Tights (or if your like like me you may know them as "the thick stockings/pantyhose"), however, are considered more timeless and usually get a bit more cred and respect for some reason.