Then I guess we won't be seeing Venom or Ock, I have a hunch that they might go for new villains which weren't shown yet (Ock was handled amazing in SM2 and Venom was screwed in SM3, but it takes more movies if they are to introduce these the symbiote story again)! However, I do hope we see GG, with a proper suit this time and I hope that they do the Gwen Stacy story, especially because we have her in the movie, its the reason why I also hope for the Goblin as well!
I think it's most likely that she'll die in the 3rd, but we'll see. I have 2 versions of the trilogy which I'd like to see become reality.
TASM1: we got Lizzy.
TASM2 (they should name the sequel The Spectacular Spider-Man ): I'd like to see 2 villains (Mysterio & Shocker, Mysterio & Kraven, Shocker & Kraven).
TASM3: The Green Goblin, Spidey's deadliest foe takes away from him what he loves the most - Gwen Stacy.
Ofc, if they introduce MJ and if they plan to have GG in the second movie, then here's how I see the 2nd & 3rd:
TASM2: GG & Gwen story. Also introduce MJ. And JJJ.
TASM3: JJJ & Scorpion story. I'd love to see Scorpion. And also have a second villain, only if it's not too much (such as Shocker for example).