From what I heard, Sam Raimi's plans for Spider-Man 4 were kind of terrible. Peter and MJ getting married, dealing with twins, The Vulture as a villain (who is one of the weaker villains of Spidey's Rogues Gallery in my opinion) and creating a new character called "The Vulturess", which also sounds pretty terrible.
I'm pretty sure the studio were foisting Vulturess on Raimi - he wanted to have Black Cat. In fact, they may even have been insisting on The Vulture. IIRC, Raimi wanted to have Dylan Baker (finally) play The Lizard but the studio felt that he wasn't enough of a draw for the main villain. Yes, as oppose to those box-office behemoths like Alfred Molina, Thomas Hayden Church, etc ...