It seems petty to point out that much of this work is rather poor. I suspect all of these creators mean well, and that matters. I'm ambivalent about pretty much all of these whipped-up objects, even the more visually successful ones. But focusing on the objects may be missing the point. Most of these creations seem designed more to spread an idea than to be owned, and to that end they've quite effectively exploited the Web design-hype machine.
What this barrage of iconography amounts to, in other words, is a de facto persuasion campaign. Considered collectively, we might call it the propaganda of concern. Because it's been spread largely by cool design blogs, which are suddenly awash in Japan-awareness products, it's appealed to an audience that's generally more engaged with Desirable New Stuff than with Serious World Events. The publicity means more than the products: Nobody who is persuaded to care has to buy a souvenir of whatever actions they take as a result. Even open criticism of these products typically concludes with an exhortation to give. So the propaganda has almost certainly inspired charitable acts well beyond raw marketplace transactions.
To me, that qualifies the help-Japan category of goods as definitively harmless—but not much more. "We felt a helplessness that compelled us to do something," the store listing for that W+K poster says. Uh, welcome to the herd: The Japan catastrophe has been a classic example of the "CNN effect." Normally it is a great challenge to persuade people to "do something" about the world's many ills and injustices. In scenarios like the Japan crisis, though, many people are anxious to feel like they're contributing to any solution or form of relief, no persuasion from a T-shirt required. In fact the short-term outpouring can outpace the creation of mechanisms to deal with it: Experts on crisis giving often say it can be wise to wait until actual plans for money deployment take shape. ("Many groups are raising money without really knowing how it will be spent—or even if it will be needed," according to a recent New York Times story; the Wall Street Journal suggested aid groups are cautiously trying to avoid uncoordinated responses, and waiting for more signals from the Japanese government.) By the time that happens, of course, most people have moved on to other concerns.
If the many sharp minds of the design community really want to "do something," the more significant challenge would involve finding ways to use their creative powers to sustain engagement over time, in defiance of the news cycle. And not just in terms of money, but the more precious commodity of attention. (Would it matter if everyone who texted a donation for "Haitian relief efforts" actually remained keenly engaged in what's happening in that country today? I think so.) This would be a more valuable contribution to discourse by design than simply amplifying the zeitgeist with a hastily concocted poster. But reacting quickly is much easier, and more psychologically rewarding. In this, the creative design minds are just like the rest of us.