Forbes – In November George Soros, John Paulson and Leon Cooperman, three of the most successful hedge fund managers ever, quietly participated in a rights offering and became major shareholders in Caesars Acquisition Co., a spinoff from casino company Caesars Entertainment CZR -1.94% that has ownership in Caesars’ online gambling assets. Their stakes–previously unreported–are all part of an unprecedented bet on the future of the $60 billion casino business in America, as states from New Jersey to Delaware and Nevada legalize a practice that the Department of Justice said was illegal just two years ago. They were joined by billionaire…