The economy in Japan is terrible, and the Prime Minster just approved a 4 billion dollar increase to the budget to help with restoration efforts. A permanent tax on citizens to help with clean-up and rebuilding is also in the works. Japan needs money.
The money that Japan is using to rebuild was originally slated for other efforts, including humanitarian efforts for other countries.
Why do I know this? Because I know someone who was going to travel to Kenya as part of a team to build a museum and help out with fair-trade crafting. That has been put on hold, and no one knows how long this will be for or if it will ever happen.
Japan makes a point of giving to other countries in need. I have no doubts that it will continue to do so once it gets back on its feet. The faster it gets there the better for all, I think.