CARLSBAD, CA — Next month, Bill Gates is retiring from his day job at Microsoft. That means his appearance tonight at the D6 conference is his last hurrah. To go out with a bang, he is debuting Windows Seven, John Paczkowski reports on the conference's AllThingsD website. Details are scant, but we've heard Microsoft was rushing out Seven to make up for the failures of Vista. Gates, Paczkowski writes, will demonstrate an "all new user interface." Which speaks to Microsoft's problems. Users are not demanding new interfaces; corporations are uninterested in retraining their staffs, and consumers are unmotivated to learn the quirks of a new operating system. Gates would have been better served by simply improving the operating system's reliability and performance — but that does not make for an interesting show.