I haven't heard anything much on the research side that would be positive medium term. Last season they tried the antibiotic/ probiotic spray from BASF which I heard was useless but I imagine desparate growers are trying it. Not Seeka anymore. The best hope was for drilling into sap and pumping antibiotic under pressure - used in apples apparently. Otherwise what is there ... rip up the vines, look for resistant plants, or head in sand.
I would say at the moment the wealth destruction in the industry would be similar to finance companies in 2007...but opportunities for tax write offs or more positively a white knight in a lab coat...