Is it really over???The rumor mill is swirling faster than ever that Cameron Diaz and her longtime singer boyfriend, Justin Timberlake, are officially over. According to sources the duo, who are usually joined at the hip, spent the holidays apart. Justin spent time at home in Tennessee while Cameron, his girlfriend since 2003, hit the slopes in Vail, Colorado and racked up some generous expeses on one of her American Express credit cards. The last time the couple was seen together was when Justin hosted SNL in New York City.

Sources close to the couple have revealed that Justin was the one who decided to end the relationship (not via Cingular camera phone like Britney). On Dec. 23, as he partied with friends in Memphis, a source says Justin told fellow party-goers: "Me and Cameron? We're done."

What could have been the cause of the breakup? Many say the nine-year-age difference (he's 25; she's 34) along with conflicting schedules (with hot movie releases and concert schedules, etc.). But over the years, they struggled from time to time with the issue of long-term commitment. Cameron is also a notorious free spirit. Over the holidays Justin allegedly hung out with ex-girlfriend Veronica Finn. "I saw him give her a warm kiss on the cheek and squeeze her hand repeatedly," an eyewitness was quoted as saying. "He left with his arm around her shoulders."

Stay tuned for all of the latest on this story, as we will bring it to you as it happens.