There's too much going on in the film. I watched it on DVD shortly after Christmas (after seeing it in cinemas back when) and just couldn't keep up!
One thing I'm really disappointed about is the overuse of romance plots. Why, again, did we have to have more of Peter and MJ's romance problems? Instead of the romance plots we could have dedicated more time to Venom or Sandman.
The movie was disappointing. I don't find it horrible, just not well done. The whole thing seems rushed and at the same time, there's so much that wasn't touched on enough.
I do want to see a Spidey 4 though. It would be weird watching a Spidey movie with a different cast, if they have to recast it, but it's a good franchise and I think it can still be salvaged for a couple of more films.