The important thing is to demonstrate that the map data being created now is an accurate representation of post disaster Japan and not just people from around the world rushing to OSM and doing what they can. I have to admit when it happened I started tracing some Bing maps in regions where the data was REALLY bad (whole towns not mapped).
If you cant demonstrate clearly to outside non-tech people that the new data is a clear representation then you can start doing something with it. That however is only true if there is enough new data in the disaster zone to be of sufficient benefit. Fair enough, that takes times, but a few roads doesnt make a map.
The really important thing is to utilise the ability to rapidly modify the map to reflect the current situation. As soon as high enough resolution areal imagery is available it not just be realised onto the main OSM editer, but also publisised through blogs, banners etc.
On a slight side note, I hope we can emphasis to the community the need to have a well mapped Japan since its current state is generally poor. That isnt to put down the Japanese mappers, im sure what they have done is good. But there is a real need to have a lot more data. It always annoys me how the OSM community takes the slant that ‘we have all the roads, we are complete’. I have heard this about Germany. Well, a lot of the roads are there, but far from all of them. And what about all the shops? all the buildings? all the leisure centres? all the speed limits? You get the picture. A map isnt complete until there is nothing possible left to map, which is of course never. From a user centred design perspective, OSM is useful in some sense with some main roads, but its usefullness increases immensely the more data of different types are included in the map.
Sorry for a massive rant, it is really not meant to put anyone or anything down, I just think this community is in an excellent place to be able to play an important role in supporting activities from this point on, and more should be done/ talked about. As soon as I can chip in, I will as much as I possibly can.