This smacks somewhat of those old blindfold taste tests.   “I hate Diet Coke.””Here, try this new soda!””Wow, it’s great!””That was Diet Coke!””Ooops!”In a similar move, Microsoft took Windows XP fans and showed them a new OS, “Mojave.” Spurred by an e-mail from someone deep in the marketing ranks, Microsoft last week traveled to San Francisco, rounding up Windows XP users who had negative impressions of Vista. The subjects were put on video, asked about their Vista impressions, and then shown a “new”