What has been described here really isn't all the different from what much of the online community has been railing against with net neutrality - content providers controlling content distribution by price per use. Really if a blog cost you 1 cent to read and a news article 5 cents then who is price controlling this?

You mentioned it would need to work across several platforms, but there needs to be an organization or company in charge assign prices, collect money, redistribute it, and take a little (or a lot) off the top for their services. In old or 'real world' business models this would be akin to a publisher, label, or other content provider. This is the exact thing that the internet has inherently undermined in many ways by making content distribution available to the individual.

Don't get me wrong, in many ways micro payments are enticing, but a completely new business model will have to emerge for them to work on the internet. I don't have a better suggestion, but then if anyone did you wouldn't be writing a speculative entry on the matter.