Not impressed at this stage. That's a cool looking Demo, but hey "Aliens: Colonial Marines" had a cool demo too. Too much lying in the industry now to get particularly excited.
That said I'm an RPG nut, so I actually appreciated what "Dead Island" tried to do more, I just think they didn't go far enough with it. What's more the thing that kind of irked me was when it turned from the somewhat novel setting of an overrun resort island, into a pretty typical "Resident Evil" overrun third world country it kind of lost a lot of it's appeal. "Dying Light" which seems to be set in South America going by the backrounds and accent (though I could be wrong) seems like it's pretty much opting for being "Resident Evil 5" re-done for first person melee combat and trying to avoid the whole "African Controversy". I can't say I'm that impressed.
To be honest, I am hoping some people take the idea of what "Dead Island" was touted as being at some point and run with it. At first I thought the guys doing that were bloody geniuses because resort islands are a great, underused location for horror. Basically resort developers, cruise liner companies, etc... are big on buying small islands and then developing them (or just flat out having artificial islands constructed) into what amount to amusement parks. The idea being that on a long cruise it gives the boats places to stop and restock, while also being loaded with attractions, stores, casinos, etc... to get people on the boat to spend tons of money on entertainment when they disembark to stretch their legs. These resorts are by their nature pretty isolated, so if there was a zombie outbreak, or someone unleashing demons with a dark ritual (maybe some cult running the corperation starts using the cruise liners to effectively ferry in sacrificial victims once they are ready....) you'd literally be trapped especially if you have no idea how to sail a cruise liner or tender. In an environment like that you can do all your favorite tropes without having to worry about justifying a global pandemic or the reaction of authorities who in many cases can be very slow to react to problems on islands like that (the jurisdiction of dealing with private islands in international waters can be touchy), not to mention given the problem with third world pirates and such it's easy to explain why security might actually have some stockpiles of guns and even moderately heavy weapons secretly stashed in case of an attack by modern pirates come to rob the place when the navy of whatever country promises to police them can't respond immediately. You don't have to worry as much about "why would there be a rotary grenade launcher locked up in the armory other than to be fun for the player to shoot" since it's kind of easy to explain why black market weapons might be there. Of course the guys doing "Dead Island" totally blew the potential of the initial idea, and by the second act it was another generic romp through ugly gray and brown textured urban blight with some jungles thrown in.
At any rate, even with the whole "parkour" gimmick the game is going to have to do a lot to sell me on why their version of choosing whether to avoid or kill zombies while chasing macguffins through ruins is better than anyone else's. They can't even claim creativity from the setting as far as I can tell.