That music video is embarrassing and I actually cringed while watching it. The sexiness is way too forced. Honestly, I think Leighton can do much better than that. I don't know if it is because I associate her with Blair, but Leighton has never really been about sex appeal to me. She's not a sexpot a la Megan Fox.
she does it better than Blake (Boobs) Lively, but I wonder if these gossip girls have anything going for them other than their sex appeal?
It's hard to say. The "teen" actors on Gossip Girl are not good - Blake mumbles, Ed overacts, Chace is lifeless, and Jessica and Taylor never get enough screen time. Penn and Leighton are the only ones who look natural in their roles - but it's easy to play the geek and the brat. Just ask Adam Brody and Rachel Bilson... whose careers are kind of non-existent right now. And when Gossip Girl is eventually canceled, they will probably go the way of their OC counterparts and fade away.
Also, talented actors can take a crappy script and do amazing things with it. So yeah, the GG writers are to blame... but I think good writing just hid the bad acting in previous seasons. Looking back, some moments were horribly acted, particularly when Serena was crying over the "murder" and Ed was pissed about his dad dying.
As for singing... I have yet to actually hear Leighton sing. Her voice is always electronically distorted, it is hard to tell what she actually sounds like. But I've only heard Bette Davis Eyes, Body Control, and Somebody to Love. (I loved Bette Davis Eyes and Body Control though)
I've liked Leighton ever since I saw her on Entourage so I hope she has a career after Gossip Girl. But right now, she hasn't done anything to really stand out, acting or singing-wise.