I feel like Dying Light is really the game this was supposed to be all along, and thus became THE defining zombie game for this gen, so far. The success of that game was very, very impressive.
Nobody really wants to remember Dead Island when Dying Light did so much more with the gameplay and overall concept (first person melee combat in a zombie game).
It's too bad, though, since I really liked the tropical island setting for DI when I originally played it on PS3...but the technical issues really held it back. Simple things like playing co-op with friends was always such a chore.