There's been a lot of buzz lately over the possibility of Spider-Man in the next Avengers film. As far as I can tell, everyone is excited and hopeful that he'll be in the next one, but I have a different opinion. Spider-Man shouldn't be in Avengers 2, or whatever they call it, for anything more than maybe a tiny cameo.
First of all, let's look at the comics themselves. Spider-Man was not a founding member of the Avengers. Of course, Ant-Man and Wasp were also founding members, but they aren't popular enough to have movies. He doesn't fit naturally with the Avengers, at least not the ones portrayed in the movie. All of Spider-Man's possible roles are already taken. Iron Man is snarky, Iron Man knows technology, and Bruce Banner knows science. Not to mention both Stark and Banner are experts in their fields while Peter Parker is a high school student. Spider-Man would be relegated to either making the jokes rejected from Iron Man, or yelling "My Spider-sense is tingling!" every time something bad happens. In combat, he can't do much more than Captain America, just with more webs.
"But Spider-Man is in the Avengers now!" You say, correctly. But look at the Avengers now. No Bruce Banner, first of all. Spider-Man's whole science thing has gotten more proficient as of late, so he's actually valuable in that sense. Second, the time when he really fit was around Dark Reign. In that, Captain America was dead and replaced by Bucky, who dressed in black and carried a gun. Hawkeye was instead Ronin, and most of the team had no compunction against killing Norman Osborn. Spider-Man was the heart and soul of the team who reminded them that they were the good guys. Look, however, at the movie universe. You have Captain America, the paragon of good, and Iron Man, having reformed as a weapon's maker, is almost as spotless in his record now. There's no dark and gritty there for Spider-Man to counteract. He's just another justice loving guy among too many.
Also, there's the omnipresent issue of movie rights being split between Marvel and Sony. No way Sony is going to completely let go of the Spider-Man movie license, but I'm sure they want a piece of that Avengers money, so they'd be willing to broker a deal. However, any such deal would be bound to come with a lot of stipulations. Either a minimum screentime or minimum number of lines, that would certainly mess with the writers, especially Joss Whedon, who tends to get all flustered by meddling. Second, there's no good way to introduce him into the series. Either he jumps in with little explanation just to be there, or they waste Avengers time making shit about him. All the films before the Avengers were written to make Avengers possible. Spider-Man is written just about Spider-Man, without the interconnectedness the other films share. Including Spider-Man would bring up far too many plot holes if he isn't part of the Marvel Movie Universe from the start. Where was he when Abomination destroyed Harlem? Was he just hiding when aliens tried to invade? So much revolves around New York in Marvel, and you can't shoehorn these events in at the last second.
Spider-Man, as his movie is made now, should not be in the Avengers, as they are now. He just doesn't fit in, character-wise or plot-wise. If a lot were to change I would be warmer to the idea, but at this point I'm against it. Now all it would bring is a pointless cash-in that cheapens both the Avengers and Spider-Man.