'Gossip Girl' Finale Spoilers: Will Viewers See Kristen Bell On Screen? [VIDEO]

"Gossip Girl" has had many secrets over the years. And one has been the off-camera identity of its narrator, Kristen Bell.

The finale, which will air on Monday, Dec. 17, will finally blow the curtain open on the mystery blogger of the CW series that has lasted six years.

Bell's snarky commentary - with fun, sarcastic inflections - has gotten far less press over the years than the designer clothes on Blake Lively and Leighton Meester. Yet the narration provided a colorful backdrop for one of the most-loved, teen-queen shows.

In August, Bell told Perez Hilton that she'd be thrilled to make a cameo appearance on the show. "I certainly would if they asked me," she said. "It really depends on how the characters unfold and if they want to villainise someone or give someone the champion stick of being Gossip Girl in the end other than me. Die hard fans know it's me. But I think normal people who watch the show care a lot more about the characters they see every week. There [are] a lot of variables."

The 32-year-old actress has had a busy year. After becoming engaged to Dax Sheppard of "Parenthood," she recently announced that they are expecting a baby. "They're so excited - they're both ecstatic," a friend of the couple told People.

The couple has frustrated fans for a while not setting a date for their nuptials. "We're not punishing America by not getting married....," Shepard, 37, told CNN back in August. "We're not going to have a party and invite our friends, half of whom can't [get married]. We're not going to ask them to come celebrate a rite they don't have. That's just tacky." Maybe it was the pregnancy that was getting in the way.

Watch Bell talk about her role in "Gossip Girl" here...