This feature over at GigaOM has quite a few interesting insights about the iTunes LP program -- while Apple sells it wholeheartedly as "the visual experience of the record album," it appears the story behind the story is not quite so clean. According to an anonymous source in the industry (note, not Apple themselves), the service didn't come from Cupertino. Instead, it was designed by record companies, and agreed to by Apple as a "concession" to "make a gesture in favor of album sales." The piece also states that Apple subsidized the creation of the first few "LPs," some of which cost up to $60,000 to assemble and license.
As you might expect with any other less-than-popular product at Apple, iTunes LP isn't exactly being thrown into the spotlight, either. While a much more visual music experience would be perfect for the iPad, GigaOM notes that it didn't even merit a mention by Jobs at the iPad announcement. It's certainly possible that iTunes LP could find a new home in the future, if bands really get behind the service and make their own (a few have, as noted, but the cost seems pretty prohibitive, especially if sales aren't that impressive), but from what this anonymous source says, the LP service is a record company concession that hasn't paid off for Apple even in the way its originators hoped.