I think you have to be careful here not to equate social valuing of the “merit and worth of products and ideas” with peer-review of the same. Some social networks (e.g. Digg.com) provide ways for users to vote on content, and these tools are useful in gaging the popularity of a concept within that culture, but they are no replacement for peer-review, if only because there’s no guarantee that the contributors and the voters are peers in any meaningful sense of the word.

Academic publishing may (and will probably have to) find ways to use these technologies, but their implementation of them will differ from the current popularity context that is web-based ranking.

College learning, even in lecture format classes, is not uni-directional. Well defined assignments can encourage peer-to-peer learning contexts as well as opportunities for self-directed learning. Open-ended assignments (e.g. essays, etc.) provide the opportunity for creative, research-based, learning.