Is Usher the new Britney Spears? That’s the question I asked myself while watching his lackluster song and dance routine during the 2008 Victoria’s Secret Fashion Show, which aired on CBS on Wednesday night. It wasn’t as awful as Spears’ notoriously dreadful performance at the 2007 MTV Video Music Awards, but it wasn’t much better either. Four years ago, when the Grammy-winning pop superstar was at the top of his game while promoting his 2004 CD, Confessions, Usher was a dazzling entertainer who exuded a unique blend of old-fashioned showmanship and modern sexuality. But that Usher — the one whose fancy footwork in the video for his anthemic smash “Yeah!” earned him comparisons to Michael Jackson — was a distant memory on Wednesday night, as he barely made an effort to work up a sweat on stage while giving one of the most disappointing public performances of his career.