These two massive articles by Walt Crawford are full of insights. Taken from Cites and Insights vol.11, nos.2 and 3 they are of great interest to anyone interested in the Library 2.0 phenomenon. I shall not begin to summarise them : your time is better spent taking a look through them! I am just in awe of anyone having the time and dedication to produce such material.
Here is the first part and here is the second part.