The tragic thing from Sony's perspective is that it's going to take a TDK/Avengers quality film to even think about reaching 700M WW this time around (unless the "overseas boom" remains that strong in the next couple of years). They might have to rely once again on the automatic growth of a few key emerging markets to save face.
Beyond that, I think it's way too early to make any relevant prediction. At this point i'd guess it can make anywhere between 500M and 700M depending on quality and marketing efficiency. Coming from three outings with mixed to bad reception, it's going to be an uphill battle for sure and if TASM2 showed something is that the Spider-Man franchise is not immune anymore, BO-wise, to the effects of a badly received film.
And aside from box office I think the main challenge will be to keep the next film's production budget under control (which implies planning the film better, and that won't be easy if the film isn't delayed at least a year) and cut down marketing costs and advertising efforts overall.
PS: I did not touch upon the subject of competition because I strongly think the film is going to be delayed at least a year but if Sony sticks to their 2016 release date, between Captain America 3, Batman v Superman, X-Men Apocalypse, Alice In Wonderland 2, How To Train Your Dragon 3, Finding Dory, Independence Day 2 and Doctor Strange (possibly) this film is bound to get crushed and crushed badly. Even if a couple of those get delayed the competition in the genre only will annihilate it. 2017 could end up being just as crowded as 2016 but it would at least give them time to polish the script, plan the film better than the last two outings and maybe offer a decent viewing experience this time.
