I honestly think they get thrown around too much. If someone has a good streak, they suddenly become the best thing ever. But I guess when someone really likes someone else they become "icons" or "legends" in their own eyes, even if the rest of the world doesn't see it.
Surprised no one's mentioned Kelly's "Breakaway" impact on the female pop-rock scene. 'Since U Been Gone' anyone? Far from legend status, but during that era she was a huge icon for that genre.
Edit: Well, even if people don't think she's an Icon, we all know she's an American Idol.
I find it sad that I make myself laugh.
In ATRL, LEGEND is when Rihanna has new candids wearing neon lipstick or Lady Gaga in a button shaped hairstyle. In reality, legend is someone who is timeless like Madonna and Michael Jackson. Legends happen to be icons (as influential fashion, politics, music or cultural figures) as well.