It'll be interesting to see how this goes. It has some intriguing possibilities, but it's also a pretty saturated market. The "market" for free information is indeed super-saturated, but the market for pay information is quite saturated as well. I already have more books, e-books, journal articles, conference papers, magazines, e-zines, etc. to read than I can possibly buy and read in any reasonable period of time. Where will reading premium blogs fit into this? I guess into the "e-zine" category. It'll be nice to get more quality stuff in that category, but there isn't really a current shortage of writing I can buy for money. So it'd have to be particularly compelling--- and also has to compete with the premium-quality-but-free online writing that's subsidized via other payment mechanisms, like blogging professors, who get paid in ways other than monetizing their blog directly.