Can be looked at in two ways:
1) Punk Rock/Melodic Hardcore influenced Metalcore
2) Nu Metal influenced Hardcore

A relatively new sub genre, it has begun to rise to prominence in mid to late 2010, with bands like Bring Me The Horizon and Architects adding very prominent melodic hardcore/punk rock elements to their Metalcore sound. A possible reason for this is the decline in appeal for traditional heavy metal, which is what lead to nu metal originating in the mid to late 90's.

Obvious influences include Comeback Kid, Alexisonfire and early Thrice.

Another example of this hardcore adding in nu metal elements such as rapping/hip hop beats etc whilst still keeping some 'heavy metal' characteristics such as occasional double bass drum beats.

A perfect example of this is Deez Nuts, which is a 'solo' project from JJ Peters, the drummer of now disbanded Metalcore outfit I Killed the Prom Queen.

How long this sub genre will flourish for is anyone's guess, but it will definitely be a favourite amongst the younger audience.