Is XMRV the cause of Chronic Fatigue Syndrome?

Here's another virus-focused article from the NYTimes that discusses the link between a retrovirus named "XMRV" and symptoms of Chronic Fatigue Syndrome (CFS), once condescendingly referred to as "yuppie flu."

Symptoms of CFS include muscle and joint pain, headache, fatigue not relieved by rest, mild fever, and other symptoms. It seems to most often affect women ages 30-50.

Retroviruses are also associated with diseases such as HIV and leukemia.