It's a sarcastic way of saying Hoorah. By putting 'Bloody' in the middle everyone will know that you are not ecstatic with the current event that is taking, or will be taking place. For best results use a rolling eye action or raised eyebrow expression. Who ever said sarcasm was the lowest form of wit?
Ben: Hey! Lets go and listen to the Lion King theme music over and over again!
Rachel: Whats wrong with you?
Ben: (Ignoring) Excellent! We can all listen to it!