Many in publishing hope the iPad will offer such a fine way of accessing information that people will actually pay for it again. Wouldn't that be nice? But in this era of user-driven content, when everyone seems to prefer the half-baked comments of their peers over a fact-checked article by a paid journalist (the few who still roam the earth), that seems unlikely. Why buy the cow when you only want a little semi-skim for your morning coffee, anyway? This video exchange (below) with Jay Rosen, a journalism professor at New York University, is interesting for the way it raises more questions than answers about the changing landscape of journalism. The value of information as a commodity is clearly only getting trickier to measure.