The Tokyo earthquake thing has been going on for a while. That in terms of possibility is a touch higher than Lil Kim hitting Japan with a missile
Yup...
I usually monitor below sites when I have plans to go Japan:
http://www.jma.go.jp/en/quake/
and
http://www.jma.go.jp/en/quake_tokai/info.html
wah both places im going next year... then how? should i postpone the buying of tickets till next year, jan?
No one can tell you when is a good time to buy the tickets because no one can predict when the big one will happen. We just know that it's long overdue. But that shouldn't stop one from planning a trip there. What you need to do is to buy travel insurance (one that covers natural disasters) right after you buy the airtickets. Since most insurance only allow you to buy 6 mths in advance, perhaps try not to buy airtickets any earlier than that if it's a concern to you.
If it happens a few mths before your trip, there's no need to cancel if it doesn't affect your hotel(s). If it affects some of the places in your itinerary, just amend your itinerary accordingly.
If it happens when you are there (touch wood), then just have to trust in Japan's buildings' earthquake code (assuming you are in the building when it happens) and just follow what the locals do...