Seven months after the DOJ filed a lawsuit to stop the $37B Aetna-Humana merger,\xa0 along with a complementary Anthem-Cigna merger,\xa0 a district judge rules in favor of the DOJ\u2014but Aetna promises a quick appeal. What does a potential merger mean for the millions of Medicare Advantage customers who rely on these mega insurers for coverage?\xa0\xa0