I agree more along the lines with JayKeeley. While I think NAD and speeds' arguments are perfectly valid, I think they are a bit exaggerated. The way I see it is this:
1) There are two "forms" of music: the progressive and the conservative.
2) What's progressive and pushes boundaries is almost guaranteed to be interesting, but not necessarily to be good. Nevertheless, it is this pushing of boundaries that I admire and, consequently, these are the bands that I listen to the most.
3) What's conservative is more reliant on pre-set styles MORE SO than the above (meaning: there is nothing that is "original" and "un-original", only degrees.)
4) These two schools are NOT in opposition with one another. Since when did we all become Hegel here? One line shoots off in the distance, the other remains more or less flat. Why should the two ever merge or conflict?
5) Both progression and conservatism are vastly important to metal.
6) Bands like Neurosis, DEP, Isis, OMG, etc. ARE representative of bands (of -core origins) that are pushing the bounds of metal. However, to say that these bands are "saving" metal is just taking a microscopic view.
7) As long as these two schools of music (and thought) exist, nothing, especially metal, needs "saving"! As I see it, it's a win-win situation.
Thus spake Zarathustra.