It looks like Hilary Duff might be reprising her role as Olivia Burke on Gossip Girl.
Buzz Focus is reporting that Hilary will be coming back for the Season 4 finale.
Perez Hilton also wrote an article about Hilary's return, and implied that she might be making an appearance next season too (probably pure speculation).
This might make me a bad Hilary fan, but I've never seen Gossip Girl. I was going to try to find Hilary's episodes on DVD but I never got around to it. Even though I don't watch, it's cool to see Hilary returning to a popular show.
UPDATE: April 13, 2011:
Several sources including Perez Hilton are reporting that Hilary Duff will NOT be returning to Gossip Girl. It looks like the original story was just a rumor.