Sending Stuff To Save The Show: Fans organized a letter writing campaign sent to the BBC (or rather postcard writing, imitating postcards sent by Freddie to Bel between Series One and Two) to protest the show's cancellation. They also have an online petition, a #savethehour twitter tag, a charity drive in the name of the cause, and have sent production company Kudos a yellow desk lamp having been informed that the BBC can't accept gifts.
What Could Have Been: Both Abi Morgan, the showrunner, and Ben Whishaw (who plays Freddie) have revealed in interviews that Freddie would have survived the beating from the second season finale. He would then go on to become disillusioned with the system that allowed Cilenti to get away with it and the media that ignored the danger he put himself in, and go a bit rogue. It would have been up to Bel to "save" him from his own demons.