Um, King Lear in Vegas would be BRILLIANT. I already think of that seedy, faded underside when I think of Vegas - especially Vegas during the day, when it's just hot and dry and not as flashy. And you also have the whole everything-for-high-stakes mentality / lack of morality that the villains fit right into. Plus the outlandish stuff, like eye-stabbing and Lear going crazy/ running around naked, and Edmund's awesome "I am so evil" speech, would be good in a madcap environment like Vegas.