Since the initial findings of the link between XMRV and ME/CFS became public in October, a flurry of new research has ensued. The study at the top of the list is currently underway at Uppsala University to try and replicate the findings of the Whitemore Peterson Institute in Swedish patients. The study is very well organized, however it's findings could be a mixed blessing: XMRV findings may be different in European cohorts, meaning that other closely related retroviruses might be discovered if new studies are pursued. Dr. Jonas Blomberg's real-time PCR assay might just be what is required to find these viruses.
Another study is currently underway to determine the atomic structure of XMRV protease at one center. This study was initiated after a link was made to XMRV in certain prostate cancer cell lines. Crystals of the protein have been grown, however this is only a first step: heavy metal derivatives must be produced, and crystals must be found that will diffract to a sufficient resolution to obtain useful data for drug development - a process that is still months away.
Another study is currently getting underway at Cornell University that will seek to determine retroviral diversity in ME/CFS patients, and try and correlate the findings with functional status in CFS patients. The project is being done in collaboration with the Whitemore-Peterson Institute and the Columbia University Center for Infection and Immunity.
Another study is getting underway at Instituto de Biologia Molecular en Medicina y Terapia Genica, Universidad de Guadalajara to determine if infecting peripheral monocyte cell lines in culture with XMRV alters the 2-5A synthethase/RNASE L pathway, and the resulting differential cytokine expression. I don't understand spanish, so it would be appreciated if someone who does could dig up more information for me!