According to http://www.jartic.or.jp/ the eastbound Higashi-Kanto Expressway is open but limited to 50-80kph while the westbound is still closed past the Keiyo Road, and there are accidents in several places holding up traffic.

And agreed with armagebedar -- I have driven in Tokyo a couple of times, and each experience was enough for me to swear it off for a while afterward.