I think what makes new bands stand out above all their peers is the approach they take to arranging their music once it's been written. Some bands are content to play the songs the same way again and again (now, mind you this does occasionally work), but in my experiences music becomes so much vital and exciting when the bands take the time to change the way they play them. Broken Social Scene changes the tempo of many of their songs and almost every guitar part changes at every show (not exactly the most original concept, but it saves their concerts from becoming reruns). There is one band in particular that has taken a really proactive approach to re-imagining their tunes: Grizzly Bear. It's hardly unexpected that a crew of chic artist types from Brooklyn would be so interested in turning each song into something new for every performance, but these guys do it better than nearly anyone I've seen. Seeing them live was a revelation because not only did it show me that every member of the band sings, they've all got a whole bevy of effects running simultaneously to turn the songs into a whole new fleet. They highlighted their spirit of change in the Friend EP, wherein they redid a few of their own songs, had other bands interpret their work and even did a Crystals cover (it's a faithful rendition but it's pretty amazing nevertheless). They have a style and a sound and so to hear them turn regular sounds into the heavy, crunchy Grizzly Bear sounds.
What's more every member of the band has their own personality that enters into the music. Obviously bassist/clarinet player Chris Taylor and drummer/keyboardist Christopher Bear add very unique elements to the music (Taylor's awesome backing vocals for one, Bear's light-delay heavy drums for another) but where the real difference comes in is the dynamic between lead vocalists Ed Droste and Dan Rossen. Ed has a much deeper voice and you could swim in it when it takes off. His tracks tend to be darker and sweeter. Rossen has a lighter, earthier sound and tends to accompany it with slighter instrumentation. Their voices appear equally on Yellow House, the bands first real record as a band (though technically) and the difference is at first so slight as to appear as if there might just be one voice, but, upon closer inspection the differences are made apparent. It's really cool to listen to Rossen sing his Deep Blue Sea and then hear Droste sing He Hit Me to see exactly where their styles part ways. Rossen is also a remarkable guitar player which just makes their improvisation and fascinating compositions easier to envy and impossible to turn off. What's more they seem to be completely unpretentious.