The opposum is the only marsupial I know of that has spread all over the planet successfully. Usually when an Old World organism gets to Australia is starts taking over. What's the possum got that the other marsupials don't?
I've eaten opossum stew several times, as well as coon. Although not my favorite meal, if cleaned properly and cooked corectly, it's pretty good. As they say, "the more hungrey you are, the better it tastes."