In a comment to an item below, John Quiggen gently and correctly points out that the insight for which I credited Brad is at least as much his:
If the Internet continues to grow in economic importance, the central role of public goods in its formation will pose big problems for capitalism, though not necessarily to the benefit of traditional forms of socialism.
What's more, he's already working on an article about it. So that's one less project I have to worry about — I can wait for him. The provision of public goods is already one of the major challenges for modern society, one that the US at least responds to fairly badly (see, e.g. the lack public transport in Miami and the really clogged roads) and it's really interesting to speculate about what we should do if the increase in importance of digitized information and tools to play with it makes this problem worse.
Brad and I have written one article which cataloged some of the issues, but it doesn't offer very much in the way of solutions. Much remains to be done here.