In the future, New Hampshire has become New New Hampshire, this in reference to how in Futurama's world, every city in America has been rebuilt over the remains of the original cities and are named "New" then the city name, leading to jokes about New New York and New New Jersey.
The scene where Eric gets thawed out in the future parodies this show, the music is a direct take on it. Much of the costumes and sets are taken from the show.
The war preparation of the otters resembles the last stand of the people of Rohan at Helm's Deep, including the sounding of a big horn and the phrase "so it begins".