As you've probably heard, there is an advisory to evacuate the northern areas of Japan up to 50 miles (80km) from the Fukushima plant. This is a voluntary evacuation, so at the moment it is not likely that things are THAT bad yet in the further regions like Tokyo.
More information.
Those in Tokyo who still feel uncomfortable with what's going on, but do not want to leave the country, I can help arrange lodging for you down here in Osaka. Please let me know ASAP so I can start searching for places to stay.
Also, keep the 180 workers who have voluntarily remained behind in the Fukushima plant in your prayers. They are the heroes of this whole thing, risking their health and their lives to keep the rest of us safe.