This isn't technically a metal festival, but it's nice to see some solid bands on the lineup. Sleep played this event last year, so the organizers seem to have a clue about good music. Depending on the schedule and timing, The Blog of Doom may take this one in. Regardless, score one more for good American music festivals. Cincinnati could learn a thing or two about including all genres in their music festivals.
For more info, check out the Hopscotch event page: http://hopscotchmusicfest.com/