You may remember that Sony were planning a Venom spin-off before the deal with Marvel Studios. There was a time when the Spider-Man franchise, which was separate from the Marvel Cinematic Universe, was in jeopardy. Sony exclusively owned the rights to make films featuring the wall-crawler but had no idea what direction they would take him in after The Amazing Spider-Man 2.
I actually loved the two movies in which Andrew Garfield played Peter Parker. It is a character that means a tremendous amount to me and I actually think those two movies hit a lot of the emotional beats and core principles of the story perfectly. As a result those movies mean quite a lot to me. However, the critics did not think so and the second instalment in the newly rebooted Spidey' universe was panned. The reason given by most reviewers being that it had the same problem as Spider-Man 3: too many villains and not enough character development to go around.
At this time Sony began frantically making plans for future movies, at one point there were talks of a villain team-up focussing on The Sinister Six, a third Amazing Spider-Man movie and a Venom spin-off. It was clear at the time that Sony were grasping at straws. We of course now know that the fate of the character would be to finally join the rest of the Marvel Universe in the MCU. He will be making his debut in Captain America: Civil War come April 29. Marvel Studios and Sony now share the movie rights to the character.
Although one thing from Sony's largely scrapped plans from that time has survived, the Venom movie is still happening. The Hollywood Reporter is reporting that Sony have targeted Dante Harper to write a Venom solo spin-off. What is slightly odd about it though is that the villain will not be associated with the new version of Spider-Man. This movie will kick-off a new, darker universe that will spawn it's own franchise of movies.
I have to say, I think it odd that they want to create a new universe just for Venom, I don't know how much mileage they can get out of that one villain. It is difficult to see how Sony are going to make a series of movies with a Spider-Man villain as the protagonist. There also seems to be too many cinematic universes to keep track of at the moment. A dark Venom movie sounds pretty good to me but anything can seem like a good idea at first, we will see.