Sinister Six most likely won't be in the third film. That's why they have the Sinister Six movie setting it up. We'll have to see how the Goblin-fight and death scene play out to get a better idea of what will happen in the third film.
So what would TASM3 be?
What we know is that the Sinister Six appears to be getting set up. The Doc Ock and Vulture harnesses almost make this assured.
Now the movies are all scheduled 2 years apart. So TASM3 will be 2016 and TASM4 will be in 2018. Coupled with the amount if time it takes to film they usually start about a year and a half ahead. That means 1 year from now TASM3 will start filming.
The options then would be for TASM3 to either:
- Be the Sinister Six, which would mean if the stand alone flick is real it would be post Spiderman.
or:
- It is some villain other than the Sinister Six, making them possibly TASM4.
The Venom stand alone concept comes into discussion as well. For a Venom movie to work he would likely need to be the anti-hero. For that to happen he would first need to be established in an Amazing Spider-Man film. He could end up being part of the S6 (I hope not) or as his own villain. This would mean either:
- Venom is the main villain in TASM3 and would have his stand alone film in between TASM3 and TASM4.
- Venom will be part of the Sinister SIx and would have his own film after the Amazing film featuring the S6.
- Venom will be the main villain in TASM4 and would have his own film after.
It's very difficult for me not to think that the Sinister Six are the next villains. The evidence points to that being the case and it would make a lot of sense.
I guess they could use Doc Ock and/or Vulture as secondary villains to Harry-Goblin in TASM3, but that might make those villains redundant. It's one thing to have Harry a little bit in TASM2 and then have him back in TASM3, but another thing to have Electro as the main villain and bring him back.
But the main point is that they don't have the time to do a Sinister Six stand alone prior to TASM3, so that means either the S6 will be versus Spidey in TASM3 with no prequel for the S6, or they will be in TASM4 with a prequel. If it's TASM4 then Venom will need to either be TASM3 or part of the S6.