"Sometimes the legend is not the whole story," insists the first full-length trailer for Diana, a biopic starring Naomi Watts as Princess Diana. But based on this underwhelming extended glimpse of the movie, Diana will spend much of its running time rehashing the parts of the story that most of us already know.

The first Diana teaser, which was released in June, silently focused on how much Watts looked like the late princess, and now it's clear why. The clips of dialogue we see in this new trailer are packed with hoary cliches that would fit snugly inside your average Lifetime movie. "You're so good at giving love. The hard part is receiving love," intones a voiceover as Diana meets Dr. Hasnat Khan (Naveen Andrews). "When you fall in love, you just keep going despite the warning lights," insists Khan in a later scene. There are still plenty of reasons to be hopeful about Diana; Watts and Andrews are both strong actors, and director Oliver Hirschbiegel has several impressive biopics in his oeuvre, including 2004's Downfall and 2009's Five Minutes of Heaven. But this gaudy, syrupy version of Princess Diana's life story is less than promising. Let's hope the actual film takes a more grounded approach when it hits theaters in October.