That’s why even Michael Jackson would have a hard time becoming Michael Jackson these days. Come to think of it, Farrah Fawcett, who also passed away this week, would never have become Farrah Fawcett if she showed up in that red, one-piece bathing suit today. In the ’70s, she became the fantasy of choice for every post-pubescent teenage boy in the country, selling 10 million posters of her iconic, high-beam smile. Now, there are so many vixens grinning seductively from so many Web sites and lad mags that no single woman could ever commandeer the public imagination in quite the same way. There is no “this year’s model” anymore. There is this week’s model, and that’s about it.There are plenty of upsides to the new unfiltered, multiple-choice pop culture of 2009. We get to decide what we want to listen to and watch, and we can listen and watch whenever we want. But there is something sad about our infinite menu of options. It could very well mean the end of true superstardom and with it, the end of the collective experience on display on Thursday night in Union Square.