Mike,
My partner and I kicked in a trail from White River CG on Friday. We didn't access the ridge because of the unstable weather but did make it to about 8200ft on the Carbon Glacier. The snow was soft but there were lots of people on the trail by the time we exited the area on Sunday. Barring any new accumulations of snow there should be a decent trail all the way to Liberty Ridge. We did see one team climb to Thumb Rock on Sat, well I couldn't actually see them with all the snow and fog, but I did hear their triumphant cheers at about 7PM.
Good Luck!