There were reports on the PPTC list that Arlington has plowed the W&OD and MAYBE the Custis trails and they are rideable to Falls Church. Haven't seen anything this evening.
I was in Vienna today and the trail looked rideable near the Maple St road crossing. I saw substantial ice and slush on the shaded area just west of Hunter Mill Rd; shaded sections in the Falls Church area might be sketchy. Good luck!