Peter is with Gwen; none of that skirt chasing like Sam enjoys. They're in the same science class. As Spider-Man, Peter develops a working relationship with Captain Stacy, even though some of Stacy's men are against it.
Harry and Peter are friends, much like in the movie. Harry is dating Liz.
Green Goblin is the villain, but with a different costume--the dark green version of the armor that looks a bit more mechanical, with spike-like protrusions (on the Spider-Man DVD as concept art; could someone post it?).
Eddie Brock is introduced here with a rewritten characterization: a good man who is married and with a child. He's a photographer at the Bugle, one of the best. When he meets Peter, Eddie is more than happy to take the freelancer under his wing. While essentially a good man, Eddie has a mob-related problem...Infinity, you know what I'm talkin' about.
Peter's origin is more in line with the Cameron script--the fruitfly eaten by the spider, which then bites Peter. The nightmare that ends with Peter waking up on a tower above the city would be included.
The final showdown would end with Goblin being impaled on his glider. No New Yorkers helping Spider-Man; they're afraid of him for now. The movie would close much like the first one did, including Harry's vow of revenge.