MetalInjection has a great article about the legacy of New Wave of American Heavy Metal aka metalcore.

As with all musical movements, some bands stayed relevant and retained their fanbase, becoming “legacy acts” (e.g. Killswitch Engage, Lamb of God, Mastodon, Unearth). Others changed their sound to establish a larger, more mainstream audience (e.g. Avenged Sevenfold). Others fizzled early (e.g. A Dozen Furies, Martyr AD), or slowly faded as the initial buzz and excitement wore off (e.g. Shadows Fall, Chimaira, God Forbid). Still others met with some kind of disaster that makes it impossible to continue (e.g. As I Lay Dying).