The good news is that more scientists are taking the disease seriously instead of claiming that it's 'just' psychosomatic. The bad news is that even if a definite connection is found, it will take a lot more time to discover a cure.
Many years ago I read a study showing that broken bones from skiing accidents healed faster than identical breaks caused by car accidents because the healing was influenced by the attitudes of the patients. In other words, broken bones are psychosomatic. I wouldn't be surprised if someday scientists establish a link between all illnesses and people's thoughts and emotions. However that wouldn't alter the fact that diseases are real and caused by viruses, bacteria, etc.
It's difficult enough for people to live with debilitating illnesses without being told the conditions are "all in your head" and they aren't really sick at all.
Even if researchers aren't able to find a cure for CFS it will be a great help to people who have it if the XMRV virus is definitely proven to be a cause.