I had the opportunity to speak with one of the researchers who attended the Cleveland Clinic conference a short while back. Since the landmark study appeared in Science last month, several groups have been in a race to replicate the findings of Dr. Judy Mikovits - preliminary results are beginning to come in, while other researchers are waiting for their virus samples to arrive. There is now reasonable certainty that XMRV is the causal agent of CFS/ME, as opposed to probable grounds at the time of publication. It is hoped that by the middle of next year XMRV will beyond a reasonable doubt be shown to be the causal agent of ME/CFS.
XMRV seems to follow Koch's postualtes, except for the first one: "The microorganism must be found in abundance in all organisms suffering from the disease, but should not be found in healthy animals." The third "The cultured microorganism should cause disease when introduced into a healthy organism", and fourth "The microorganism must be reisolated from the inoculated, diseased experimental host and identified as being identical to the original specified causal agent." has yet to be shown. However, the main criticism of Koch's postulates is that it does not account for asymptomatic infections.
It is worth noting that there was considerable attention paid to possible therapeutic agents for ME/CFS. This is still very much of a gray area at this time - and it will be several months before it is known which existing HIV drugs will work against XMRV - only a couple Reverse Transcriptase inhibitors, and Raltegravir have shown early promising results. This in itself has already led to a few doctors prescribing AZT off-label to ME/CFS patients outside of clinical trials, in addition to a handful of individuals purchasing the drug online from internet pharmacies - however AZT IS NOT a drug that should be taken without medical supervision under any circumstance.