In December 2012, ICANN announced the start of work to collect and publish data which would help correlate performance of L-Root with growth in the root zone. The first set of measurements concerned with identifying growth in the root zone, was published last month.
Details of the project can be found in the document “Root Zone Scaling Measurements at L-Root” [PDF, 5 MB].
Data collection for performance characteristics of L-Root has also started, and initial publication of performance data is scheduled for March 2013.