The other tab for this song is wrong?if you listen closely there are clearly 7 chord changes:

    G     Gsus   G       ?    D     G    Cadd9  
         
E----3-----3-----3-------2----2------3----3~------
B---0------1----0--------3----3-----3-----3~---------------
G---0------0----0-------4----2------0-----0~-------------
D---0-----0-----0-------0----0-----0------2~---------
A---2-----3-----2-------0----0-----2------3~-----
E---3------3----3-------x----x-----3------x~--------
Play the first two G chords with your middle finger, ring finger and pinky? it makes it a lot easier when you change to the Gsus that way.     
You?ll have to figure out the timing yourself, but the chords are as right as they get.
Brand New is awesome!