There have been a couple of recent articles on InfoQ about JCR and/or REST. In case you haven't seen them, they're all worth a good read.

Interview with David Nuescheler, from Day Software: http://www.infoq.com/articles/nuescheler-jcr-rest
InfoQ architecture and use of JCR: http://www.infoq.com/presentations/design-and-architecture-of-infoq

Best regards,

Randall