Here's a list of some of the upcoming zombie releases planned for 2015. Some will be theatrical, others will be streaming or VOD. As many films are made by independents release dates are subject to change. Only movies in post-production or that have actually been finished are listed.
METELETSA: Winter of the dead: http://winterofthedead.com/
Dead Rising: Watchtower. https://www.facebook.com/deadrisingwatchtower/timeline
Kitchen Sink: http://www.upcominghorrormovies.com/movie/kitchen-sink
Scouts vs Zombies: http://www.upcominghorrormovies.com/movie/scouts-vs-zombies