One can be a nihilist in how one sees the ontological reality of the world: there is no meaning to be found, there is "nothing" out there. Only systems to be created by dishonest philosophers.
And one can be a nihilist in how one reacts to that ontological reality: by being paralyzed by the "abyss" of meaninglessness, or of lapsing into pessimism a la Schopenhauer.
Nietzsche is a nihilist in the first sense, but not in the second. There is no meaning to be found, but this is not his last word. There is meaning to be created, "life" to be affirmed. This is why both posters above can be right: Nietzsche is a nihilist, and he rails against nihilism.