(all pics thanks to Getty Images)

Big night for Ms Britney Spears in Vegas...the debut performance kicking off her 2 year residency of her 'Britney: Piece Of Me' show at The AXIS inside the Planet Hollywood Resort and Casino...looks like some of our FAV Star artists where there for the fun too from Miley Cyrus, Adam Lambert, Selena Gomez & Katy Perry. and more...

Here's a little sample of her in action...what do you think?? And who cares if she MIGHT be lip-syncing??? Goooooooooo BRIT!!! ;)