For what it's worth, I went through the entire game without using the cover system. It's not like Gears or GTA IV where if you leave cover, you die. The accuracy for guns at long range is poor, so for me it was pointless anyway. Real men run up to zombies and suplex them.

I'd say it is entirely more melee-orientated than cover-based, and I'd struggle to call it a cover-based shooter as much as I would to call it a survival horror game.