Found this over @ Gizmodo.  Here is NASA’s explanation of the object:

If this interpretation is correct, two small and previously unknown asteroids recently collided, creating a shower of debris that is being swept back into a tail from the collision site by the pressure of sunlight. The filamentary appearance of P/2010 A2 is different from anything seen in Hubble images of normal comets, consistent with the action of a different process.

Basically, that’s what the THINK it is.  They aren’t 100% sure.  But I think myself and my fellow readers over at Giz know exactly what it is…