Most deals Marvel previously made with various movie studios include a ticking clock for character rights. If a studio decides not to make a movie within a certain period of time, the rights revert back to Marvel in most cases, and we recently saw this happen with Daredevil. That's not the only character to come back to Marvel, as it has been revealed that they've also regained rights to Blade and Ghost Rider.
Kevin Feige made mention of this in the latest issue of Entertainment Weekly and discussed the reason why characters are coming back to Marvel: "Whenever a character comes back to us, it’s usually because the other studios don’t want to make the movies anymore – and that usually means the [previous] movies may not have been particularly well-received."
We wouldn't get too excited about a new Blade or Ghost Rider movie going into development right away. Marvel currently has a packed slate, so it's unlikely that we'd see these characters show up in the next few years. Also, there has to be some worry about how characters like Blade, Ghost Rider, or The Punisher would fit in with the more family-friendly cinematic universe they've established at Disney. It's unlikely we'll hear much about these characters getting their own movie any time soon, but we'll let readers know as soon as anything is mentioned.