In a recent Entertainment Weekly article (focused on Phase Two of Marvel's intertwined movie series), Marvel Studios president Kevin Feige casually dropped that the rights for two classic Marvel comics horror icons had reverted back to them. Ghost Rider, fresh off a flop of a sequel starring Nicolas Cage, was let go from Sony (who has a vice grip on the Spider-man film rights) due to lack on interest, and Blade was released from New Line Cinema (presumably because it was seen as a franchise that had run its course).
While Feige points out that Marvel Studios isn't chomping at the bit to reboot these horror comic franchises, the potential for a shared horror comics universe under the umbrella of Marvel is an intriguing one. Indeed, Blade (along with characters from his mother series, "Tomb of Dracula", such as Hannibal King, Frank Drake and Dracula himself) frequently crossed over into Ghost Rider's books and even formed a team of supernatural themed heroes called the Midnight Sons (think of the more metal version of the Avengers).
If Marvel was smart, they'd start a whole new horror themed Phase One, and have a horror related Marvel movie come out each Halloween, culminating in a Midnight Sons film staring Dr. Strange, Ghost Rider, Blade, Morbius, Werewolf by Night and Man-Thing.