Clinton vs Obama feud is good for both of them
For Obama, it gives him a chance to address the issues he would get hit with in the general election. His response thus far shows he badly needs the practice. Better now than later when it will matter much more.
For Hillary, this long battle has shown how incredibly tough she is, and she has fully moved out of Bill's shadow and become a big political force in her own right. Her future in the Democratic party is very strong.