i think every filmmaker has a zombie (or at least some kind of cliche horror) film in them, and personally i know i'm going to end up doing one sooner or later.
there are so many different things you can do with zombies that the possibilities are endless - where do the zombies come from, how and why are they created, how can they be they, are they fast or slow, intelligent or dumb, organised or independent, and then you can wrap whatever storyline you wish around them and throw in any characters. i think it's an interesting genre that should be studied more. there are people that would argue that 28 Days Later is not a zombie film because they are not zombies, they're called 'infected', but genre-wise it's a zombie film. in fact i would argue that Hitchcock's The Birds is, genre-wise, almost a zombie film - just watch it and imagine a zombie instead of every bird and you'll see what i mean, it's survival horror just the same and makes similar social connotations.
i've got (what i think are) some very good ideas for my zombie film, which i hope to make within the next year or so, depending on budget, time and finding a cast and crew. in fact i've had enough ideas for about 3 zombie films so i may have trouble deciding which to use.