There are many things we have to take into consideration such as:
1) In Arab countries, the individuals are far richer than the government, so donations are named by the individuals and not the countries. Such immense donations, immense as they are. (And believe me THEY ARE... I've seen what Gulf Arabs donations could do), they don't make it to the news and same applies for any other Western individual donation (added to it the secrecy of a Muslim's donation). Governments donations are those that make it to the news for a variety of reasons.
2) Living in an Arab country, charity is almost seen EVERYWHERE. The easiest and fastest community to raise a fund or organize charity work is seen in a Muslim community, however poor the individuals are. Simply because charity is HIGHLY encouraged in Islam in a way no other ideology has.
3) Most Arab countries suffer from an economic system collapse (mainly because of the non-islamic, non-scientific handling of economic issues; believe it or not, the USA and Japan's economy follows Islamic economic rules more than any other Arab country), which is why no HUGE donations are to be expected from these poor governments, what's expected from the governments is mainly offering human resources such as medical aid, temporary residences...etc. which is what's really happening now on a higher scale than money donations. Which is why major HUGE money donations are given by the individuals not the government, as I mentioned before.
4) In Islam, charity highly includes 'secrecy' in its meaning. Except in certain cases when charity is made in public to encourage the deed. I don't think this is the case in the Asian Tsunamis because donations are flooding from all over the world even some Asian countries have temporarily stopped accepting them until proper donation-handling systems have been put. India being an example.
5) I must say that I always hated the way people brag about donations, in this case or any other. Donations should be given for the sole purpose of helping someone, without making this person shameful or highly aware of this aid. If anyone of us faces a financial problem and recieves help from someone, I wouldn't like this someone bragging all over the society with this aid. You don't need to have a certain belief to understand that. Moreover, muslim's donations are given for the sole purpose of pleasing God by helping a person in need. Not for having a better public image...etc.
6) Finally an IMPORTANT NOTE: Those who say that this Tsunami is a punishment and so... that is plain superstitious non-islamic non-religious crap. Islam has made it clear that this life isn't a place of reward/punishment.. it's a place of deeds and work. You simply reep what you sow. Which is why Islam came encouraging work and knowledge seeking as evident with the major scientific uprising in all scientific fields; philosophy, theology, astronomy, medicine and law during the Islamic civilization era exdending over more than a century especially from 813 - 833 C.E. which may be considered the 'golden age' of science and learning. But to contradict all of that and say the Tsunami is a punishment and stuff like that is so sad to hear. This isn't a place for punishment or reward as regards a person's sins/beliefs. If it were, then no disbeliever would find a drop of water to drink. Neither is any individual's beliefs a reason for punishment (by another individual) as clearly stated in the last line of this verse:
Say : O ye that reject Faith
I worship not that which ye worship,
Nor will ye worship that which I worship.
And I will not worship that which ye have been wont to worship,
Nor will ye worship that which I worship.
To you be your Way, and to me mine.
My condolences to the victims of this disaster, I really hope they get over it. The Asians have a marvellous ability to rebuild and prosper... who would have known that Japan -a group of islands struck by 2 nuclear bombs- would prosper into this amazing economic and scientific giant... maybe it was this nuclear tragedy that gave these people a thrust towards progress and prosperity... I really hope for the best.