This is a sweet acoustic album, and quite simply it is a mirror reflection of Gillian Welch/Dave Rawlings - in both tight harmonies and dual guitar work - and/or Simon and Garfunkel, or just Paul Simon in his early solo work. Their own and real names are Kenneth Pattengale and Joey Ryan and they are from LA.
If you want confirmation, you can download their 2011 album free here: http://www.themilkcartonkids.com/?page=music
That's quite sweet too. Actually, that's quite brilliant.