Latest clip reminds us of her 2001 smash — and it’s not the first time the pop superstar has sampled her own video catalog. By Christina Garibaldi Britney Spears in “Til The Word Ends” Photo: Jive With Wednesday’s release of Britney Spears’ new video for “Till the World Ends,” the pop diva showed she can dance her way through anything — even an apocalypse. Now, although “Till the World Ends” takes place in the future, it’s hard to watch it without feeling transported to the past. The edgy look, steamy scenes and pulsating dance moves take us back to Spears’ 2001 hit “Slave 4 U.” Some of the key elements of “Till the World Ends” mirror “Slave,” from the videos’ sweaty dance scenes to the sexy wardrobe changes to an almost identical scene in which Britney sits among a group of sultry dancers. And this isn’t the first time the princess of pop has paid homage to herself. Spears’ over-the-top videos have typically featured some distinct elements: memorable story lines (“Toxic”), standout choreography (“Oops! … I Did It Again”) and midriff-bearing outfits (“I’m Not A Girl, Not Yet A Woman”). So we can’t say we blame her for looking back. In 2008, Spears released her video for “Womanizer,” which gave us a case of d