This is basically what we already knew. It doesn't explain how the system is integrated with data providers such as google.
PRISM is not an undisclosed collection or data mining program. It is an internal government computer system used to facilitate the government’s statutorily authorized collection of foreign intelligence information from electronic communication service providers under court supervision
http://www.dni.gov/files/documents/Facts%20on%20the%20Collec...
"PRISM == Collection directly from the servers" written in the top secret slide apparently made in his agency.
But we aren't upset about what PRISM is doing we are upset about what the NSA is doing. So clearing PRISM's name is pointless and could just be a way to mislead without directly lying. Or he may just be lying.
[1] https://twitter.com/ggreenwald/status/343470800784982016
These are the key words. It appears to be a pipeline, from government to independent corporate networks. The government uses this "system" to retrieve whatever they want to retrieve, and whenever they want to retrieve, the information from independent corporations, following of course the legal procedures.
Well, we can all go to sleep better now.