I'm not sure what the news is like in America, but around here the discussion will most likely be about the eruption of Mount Ontake.
At 11:50 AM local time, the volcano erupted by spewing a massive cloud of ash into the air. Hundreds of hikers were on the mountain at the time, and dozens are injured, though I haven't heard details on how bad yet. Seven hikers are missing.
Volcano eruptions aren't exactly rare in Japan; a new island has been quickly forming in the Pacific Ocean from a volcanic eruption over several months; that island actually swallowed a second island. And I wrote about my visit to an active volcano in Hokkaido which erupted most recently in 2000.
The event is major national news, of course, but Tokyo is over 200 km away and certainly not at risk. The nearest major cities are Nagoya and Matsumoto, neither of which are in any danger either. Hopefully everyone currently on the mountain can be safely removed by the end of the day tomorrow.