The release date for Hitman has been pushed back from the original December release date until March of 2016. IO Interactive is being very candid about how massive the project is for them, and has thus delayed the release until all the parts can fall into place correctly.

Hitman delayed until March of 2016 so that they can get it right.

　　It’s safe to say HITMAN is the biggest venture we’ve ever undertaken at Io-Interactive. Not just in terms of scope and ambition but also in terms of the size of the game world itself. The playable area and density of our locations goes beyond anything we’ve built before. We’re striving to create a series of living, breathing worlds in those locations and we get pretty obsessed about every detail that you’ll experience.

　　They continue and explain that the levels alone are significantly larger than in Hitman Absolution, and thus any Hitman game before it. The Paris Showstopper level alone is but among one of many different large levels in the new Hitman, with 6X the number of unique NPC's alone. This isn't an easy task, and while they have certainly underestimated their initial release date, being kind to fans and explaining the delay months before that initial date is much appreciated. Hitman has always been a fantastic, if cult-like, genre. Perhaps this will recapture the essence of Hitman.

　　Below is IO Interactive's statement on precisely why they want to delay.

　　We want to make absolutely sure you all get the best possible experience when you join, so we’ve made the difficult decision to move the initial release date to March 2016. These few extra months will mean we can add more to the launch content of the game, more than we had originally planned, and then follow with a tighter frequency of updates, which ultimately will create a better game for everyone. And in the end, that’s what we’re all looking for.