Just tuned into the Boston Approach Final Vector feed...BOS is closed for "at least" 45 minutes because of "nil breaking action reported by a Continental 737 on runway 4R." Since the RVR is below minimums for the other runways, the final controller is holding most inbounds over NABBO intersection on the 4R localizer, 10 mile legs.
Pretty nasty out there, but it makes for some interesting operations!