Card Player – MGM, Boyd and Golden Nugget have all officially filed to get another extension on their respective Internet poker plans in Nevada. The firms — which were all approved for Internet gambling last fall — appeared on the agenda for the October meeting of the state’s three-member Gaming Control Board. According to the rules on the book in Nevada, firms apparently must move forward with their business plans within six months of being approved for the activity by state regulators. However, given the extensive testing and preparation that is needed to debut Internet gambling and poker some firms…