For a while now internet writers have been "fan bating" Marvel fans. Claiming that Iron Fist is in development hell and he is being replaced by the Punisher in the defenders. Anyone who really knows Marvel knows that the Punisher is a murdering vigilante and the defenders line up are just vigilante's/Crime fighters. They don't kill nor do they condone what the Punisher does. Especially Daredevil, in fact season 2 of Daredevil will be focusing on the contrast between Daredevil and Punisher. This doesn't mean Daredevil and Punisher are enemies, they are friends but its a little more complicated than that. They have fought many times due to disagreeing with each others methods.
This doesn't mean to say Punisher won't get his own series because I'm pretty certain he will but he won't be a Defender, again this doesn't mean he won't be in the Defender series. It just means he won't be a member of the defenders and he won't replace Iron Fist.
Iron Fist isn't going to come out untill 2017 or at the very earliest, late 2016 (personally i think July 2017). Marvel has only just started releasing information about Jessica Jones and that is out this month. Daredevil is by far the most complicated and difficult origin to cover out of the Defenders and they nailed it. They know exactly what they are doing with Iron Fist. The biggest trouble they are probably having is the costume.
The reason Iron Fist is now coming out after Luke Cage is because Luke Cage is going to appear in Jessica Jones so it makes more sense to have his show next instead of making fans wait to see a character they are already familiar with when they can build long term excitement on something no one has seen yet. It makes more sense having Iron Fist last. It is true they can spend more time on him this way, but it doesn't mean they are having trouble developing his show. Also the rumor about Iron Fist being a Netflix feature film is a lie. Why would they decide to change the format when this one works so well. Anyone who knows about Iron Fist and has watched Daredevil should be able to imagine how perfectly his story fits into that format.
Talent-less writers fan bating to get views will not make Marvel speed up the announcements, they don't care. They want you to speculate it shows just how excited the viewers are. You guys are dying to hear what is happening but if you knew anything about Marvel you would know that everything will go on as planned and any difficulties that are involved will only enhance the finished product. Excelsior. Rant over.