This is 2NE1, one of Korea's top girl band, who are scheduled to release their English album sometime this year with the album executively produced by will.i.am. Out of all the Kpop bands who are said to be focussing on the West, most said this group has the most potential to be big.

Some of their upbeat songs:
http://www.youtube.com/watch?v=j7_lSP8Vc3o (I Am The Best)
http://www.youtube.com/watch?v=KQEabAesufg (Can't Nobody English Version)
http://www.youtube.com/watch?v=3yW13T2sfKg (Go Away)
http://www.youtube.com/watch?v=J5ekB4l-6wg (Don't Stop The Music)

Their mid-tempo/ballad:
http://www.youtube.com/watch?v=5n4V3lGEyG4 (Lonely)
http://www.youtube.com/watch?v=NGe0hHvAGkc (Ugly)

Getting to know the band: http://www.youtube.com/watch?v=N7GV48AEMmE

So do you think they will be successful, or just crash and burn??

They will find the UK very difficult to break, the rest of Europe I think they can achieve some success. I know they've been promoting in America as well. Anything is possible I suppose.

OMG I LOVE 2ne1! They're my favourite group at the moment, here is a new preview of one of their songs with will.i.am, they played it in a Korean club:

http://www.youtube.com/watch?v=x-ve_Tu5-7M

I think if they put in the promo, and really, REALLY go for it, then they could be successful. They've got the talent and they are certainly unique among their genre.