A lot of so-called hardcore bands these days sound more like metal than some metal bands. Five years ago they were all aping Slayer, now they sound like Swedish metal...
I agree with whomever said that when they think of hardcore they think of Bad Brains, Minor Threat, etc. Without that stuff cross-pollinating with metal we would all still be listening to Judas Priest. Wait, some of us still do.
As far as current hardcore goes, I listen to a lot of hardcore from other scenes like Japan, Finland and Brazil, they seem to base their music more off the play as fast as you can raw punk, rather than the straight-edge metalcore that seems so predominant in the US scene.
However, there are a lot of really interesting "screamo" bands in the US that I don't even know if I would call hardcore, just really fast, spazzy screaming no-wave noise. I like a lot of this stuff but most of it just flies over everyone's heads. Bands in this idiom to check out would be Honeywell, Angel Hair, Vida Blue (now Ten Grand), City of Caterpillar, A Trillion Barnacle lapse, etc. etc. etc.
Check out these labels to see where the US "screamo" hardcore scene is going: Level Plane, Electric Human Project, Clean Plate (also grind!).