The partial retraction of the Science paper explains why no one can find XMRV using VP62 as the reference virus. VP62 is an artificial construct, it seems, and not a naturally existing virus.
So for me, this can explain why there have been so many negative studies, why Alter and Mikovits have detected HGRV's where others haven't, and it explains the discrepancies between Mikovits' and Alter's viruses, or variants.
I'm still working out what it all means though, and haven't got completely up to date with all the details yet.
The BWG was pretty irrelevant for me, because there were so many unfavourable factors and unknown variables in it anyway. I never expected it to show more than a mixed result anyway. Although I must admit that i was surprised by the results. My understanding is that Mikovits was not free to choose her own methodology for the BWG, although I don't know the details.
Let's not forget the multiple prostate cancer studies and the two ME studies that found differences between ME patients and healthy controls. Even if there is no virus involved, then these would be very useful biomarker studies. Something is going on.
I agree that there are more questions than answers right now. But the BWG group was just one study. I don't think that undue prominence should be placed upon it, especially as the methodology used might have been very far removed from Mikovits' ideal methodology.