I think this is useless. Apology means nothing.
Do you know till this day, many Chinese and Koreans still hate Japanese ? And if you think its only restricted to the older generations, think again.
Many haters of Japanese are the younger generations
Quite being such a pessimistic antagonist.

I imagine you have skills that far exceed statements like this, so please use them. I must concur with LinDynasty and Pattie.
SIMPLE LOGIC - what can they do besides offer an pology? It's past. Already done and over. What can they possibly do now, Mr. Club? Apologies, memorial services, special tributes, historical upgrades in possibly inaccurate learning material for public schools, etc. that's about it. Things along those lines. in all fairness, I agree that an apology in itself, although significant considering where and who and why, does not carry as much weight as additional actions such as those I mentioned above. Should the apology be coupled with even a few such things, it would be a diplomatic event quite ground-breaking in its implications of future relations, which have been shaky now for many years. The apology in itself is unexpected, but certainly noteworthy, be it only words. It's still quite a significant gesture from the Japanese.
On the other note our fine William mentions, I agree that it would be only fair to apologize to China, as well. Apologizing to only Korea makes little sense, considering the scope of things. It could very well be taken as an insult to the Chinese, if one is not presented to them as well, and those who know this time period deeply, more than understand why. William raises a superb point about China's suffering. This is one area of Chinese History where my studies readily excel. So, it is highly questionable why one has not come for China.
If one is not raised for China as well, I suspect the current political hatred between them is the likely answer for one not being made. Not past relations. It is no secret that the two are ideological opposites in many ways, and this is stirring more unrest these days as the world becomes increasingly unstable in foreign relations. I honestly think Japan is trying (at least) to be an 'Asian good guy' and absolve their former image, because of this very fact. It is very smart, now more than ever, to make their positions known, and preferably positively. Also, with rising tensions between North and South Korea escalating rapidly again, and China being more persistent than ever about holding rights to Taiwan, it is the perfect opportunity for any Asian nation to improve its image and relations with neighboring countries, with the right steps, and by avoiding similar aggressive policies and favoring more benevolent actions, however large or small in scale. One could argue Japan is doing this as a form of political and time-reasoned convenience, rather than sincerity, but I believe they harbor both.