I saw it at a 11.30pm scrrening on friday, and thought it was good, but nothing special. There were some truly great moments in there but as a whole it didn't play out right. Its almost as if there were two really good movies shoehorned together to make one average one.
SM3 should have introduced eddie brock (though not venom), developed the new goblin as a bad guy, and have the sandman as the main villan. End the film with the sandman being defeated by water (as happens halfway through sm3) and new goblin being injured/stopped but not killed, and Have mary jane leave peter toward the end.
Then for SM4 introduce the Venom Symbiote, have sandman re-emerge, and form an alliance, then have Spidey and new goblin team up.
The only thing I actually disliked about the film was killing off harry - he'd only just become an interesting character. Also there didn't seem to be a reason why sandman suddenly stopped fighting and asked for forgiveness.