How Does Lady Gaga Compare to Madonna?

By now (that is, six hours after its release), you've probably already heard Lady Gaga's latest single "Born This Way" (and if you haven't, you can listen here). If you were born before 1990, you probably also thought, Hey, this sounds like a Madonna song! Gaga's been compared to Madonna since the start of her career (they're both trend-setting pop stars with a love of unique bras who aren't afraid to throw their sexuality in people's faces), but now she's making a claim to the Material Girl's musical mantle as well: "Born This Way" borrows its melodies from "Express Yourself." Is mimicking Madonna canny, or tired? Is Gaga Madonna's rightful heir? And will she have her staying power?