Tim Bray's "Content-free" is a great piece on why the term "content" is so objectionable. He raises some good arguments, but misses my favorite one — one of the origins of the term "content" in technical speech is the idea that you can separate the "content" of a Web-page from the "presentation." Indeed, scripts that present "content" to users are sometimes called "decorators."
Now that the Web's in its second decade of common use, it's pretty clear that "content" and "presentation" are never fully separable. This is a lesson that was already learned in other media — for example, when movies progressed from being a single, locked-off camera recording a stage-play and instead began to integrate the limitations and the capabilities of film into the "content" of that film.
John Perry Barlow made this point well in his introduction to my essay collection Content (a title chosen for largely ironic reasons). It's also a point that David Byrne makes very well in the brilliant How Music Works, where he discusses the move to record each musician separately and mix the "content" in the studio, and how that produced a manifestly different kind of music than music where all the musicians played together.
In other words, "content" isn't just pernicious for Tim Bray's excellent reason ("'Content' has the stink of failure; of hustlers building businesses they don't actually care about"), but because it implies a harmful untruth: that there is a clean line that can be drawn between "content" and "form." Where this untruth flourishes, people who produce "content" that is, in fact, optimized for the form of "content whose form will be determined later" go about claiming that they have found the neutral, form-free, platonic ideal of content. Instead, they've constrained their content by eliminating all the form-dependent elements, and thereby constrained their ability to communicate the full range of human ideas.
"Content" has the stink of failure; of hustlers building businesses they don't actually care about. Which is icky and usually doesn't pay off.
Enough with the negative findings, because there's something important and positive to say here: If you're building something that's used for communication, and you find that people are using an idiomatic name for what they're sending and receiving, you're probably on to something.
But if you're about "generating content" you're dead.