EA has been on the App Store for a long time. Say what you want about subscription minigames and in-app purchases, but recent release of Tetris and Bejeweled demonstrate that EA has a good play. Activision, on the other hand, still doesn't quite get the App Store, and the result is games like Call of Duty Black Ops: Zombies.
Not that this latest version of this game is bad. In fact, it's a pretty faithful recreation of the popular variant of the console military shooter. You shoot zombies, earn money to buy weapons and upgrade your map, and then shoot more zombies to earn more money. The graphics are fairly high level (though don't compare to games made specifically for iOS like Infinity Blade), the virtual controls work just fine, and the experience is more or less equivalent to the real thing. There's even a dual-stick shooter called Dead Ops Arcade hidden in here (originally an easter egg in the console title) to make that US$6.99 purchase price a little more palatable.
But this is really just one mode of a console game ported over to iOS, and a year-old console game at that. Hopefully Activision will step it up in the future, because EA's developers (among others) know the've got to do better than this to compete on the App Store. If you're a fan of this one, you can grab it (though I'd say wait until it goes on sale), but everybody else can pass for better titles.