FAQ for
Futurama: The Beast with a Billion Backs (2008) (V) More at IMDbPro »

Not really. Apart from the continuing presence of the dimensional rip which occurred at the end of Bender's Big Score, there is no follow up to previous events.

This is noted in a deleted scene, in which Bender stops the opening sequence when the narrator shows the rip in the universe other than the rest of the 63 plot points "previously on Futurama".

There has been some debate over the internet over the official meaning of the title. But Futurama's executive producer David X. Cohen confirms on the audio commentary that the title refers to the phrase for sexual intercourse "the beast with two backs", popularised by William Shakespeare. Incidentally, this phrase was also referred to in the episode "Spanish Fry" where it was the name of a sex store "The Beast with Two Bucks". Also, "The Beast" is a reference to Yivo, and the "Billion Backs" is refering to all the humans he captures with his genticles.