She is so back.

Britney Spears is gearing up to perform live in Bryant Park on Good Morning America on December 2 to promote her new album and single, "Womanizer."

Sources close to the situation said, "Everybody wanted her - she was the big get - but Good Morning America and ABC outfoxed the Today / NBC people. "

NBC suits are said to be "fuming" at losing her.

While Britney Spears has yet to decide if she'll do an interview on top of the lip-synching performance, she's definitely coming out with a revealing MTV "documentary" in which she talks about her trying last two years.

The December 2 will take place on her 27th birthday! It will mark her first live performance since ... um, you know. If you don't know, see below!

Britney Spears: Gimme More, 2007 MTV VMAs