I think if handled right Mysterio could be a very convincing and maybe even menacing villain. Also since he's a special effects guy you can have great fight scenes with Spidey fighting robots or movie monsters. Mysterio is a villain that just doesn't get enough attention and I think he'd be great, although a costume redesign is a must.

I've always wanted to see Scorpion in a movie ever since watching the 90s Spider-Man cartoon when I was a kid.

I would like to see an Amazing Spider-Man Trilogy. Have Norman Osborn as a background villain in the first two movies who is in part responsible for creating the villains that Spider-Man faces. In the third one he changes himself into the Green Goblin. As for the second movie villain:

Mysterio, Scorpion or Vulture 
 
Not old Vulture. Younger Vulture. 

I think maybe since this movie seems to be including Peters parents and not following the amazing spiderman story with them being CIA agents I think they may go with the ultimate story with his parents accidentally creating the venom suit and Peter and Eddie being childhood friends and both science nerds, Conners is also involved, so we could see him back in the sequel, this story also has quite a dark undertone to it which is what webb seems to be going for with the first movie.

I dont think Webb would want to do a goblin saga so soon after Raimi's interuptation of it, so maybe we'll get the venom saga stretched over two movies. The second amazing spiderman with the creation of the symbiote suit with Peter using it throughout the film while fighting a some other Spiderman villain, dunno who that could be, then getting rid of the the suit by the end and then in the third film we'll get Venom. Hopefully Venom will be done with some justice then, i mean Eric Foreman as Brock Christ Raimi what were you thinking.

Of course this is all guess work but I think it would be brilliant on screen. Getting ahead of myself here I can hardly wait for ''The Amazing Spiderman'' let alone its sequels ha!