The blogsphere brouhaha on the subject was begun by Jeanne D'arc, who admirably summarizes it here, with links to posts by others. Briefly, she admires Gates's decision to give 95% of his fortune to charity, likes what he's doing with the money, and believes it outshines whatever sleaziness was involved in the building of Microsoft. To which the counterpoints are, very roughly, these: There's something wrong with a state of society in which the best chance for the worlds' poor to get their vital needs served is for a rich guy to spend the money on a whim (Gates himself would concur; he calls that "a failure of capitalism"). That it was a pattern typical of nineteenth century imperialism to reduce conquered people to utter poverty so you could exploit them and claim credit for serving their needs all at once -- as if Gates was personally responsible for the actions of the IMF (which has, by the way, been a bit self-critical, of late). And boy, that Bill Gates sure is sleazy, isn't he?
Because, despite all that, I can't stand Bill Gates, I'll add two points that I don't think I've seen elsewhere.
First, it's easy to exaggerate the degree to which Gates is sacrificing his childrens' welfare. Gates's fortune is estimated at $43 billion. Five percent of that, divided three ways, leaves each of the kids with more than $700 million, which would put them comfortably on the Forbes 400, albeit toward the bottom of the list. The life of the idle rich is still theirs if they want it.
More seriously, Microsoft's business practices do themselves have at least a potential negative impact on the third world. Specifically, many users now have no reasonable alternative to running Microsoft software (or think they don't, which amounts to the same thing). It has long been Microsoft policy to keep it that way, and they're pretty bloody in trying to do that, e.g., with anticompetitive discounts ("Under NO circumstances lose against Linux", its salesmen were warned, even if they have to give the stuff away) which are arguably illegal in Europe. Between that and Moore's law, a very significant component of the cost of a modern PC is Microsoft license fees, and the company is using all its significant power to keep it that way. It's not a sure win -- Linux is out there, and OpenOffice can at least read most Word documents -- but with digital rights management trickery like Palladium in the offing, which has the potential to keep you from reading any document in Word-some-future-version unless you're running Microsoft-approved software on a Microsoft-approved platform, it's not a sure lose either. And licenses that milk the most money possible out of the first world, are licenses that the third world can't afford.
: That assumes that he manages to get essentially all of the 5 percent to the kids -- a good bet, I think. For the Gates hoard to retain enough value to keep its relative place on the list may be slightly more doubtful, but there are limits; something like three quarters of it is Microsoft stock, but that leaves over $10 billion of other stuff, which is very conservatively managed.