Titan has passed rigorous acceptance testing
Reg quote: The entry of Tianhe-2 at the top has pushed down other systems in the June rankings, of course. The "Titan" XK7 ceepie-geepie at Oak Ridge National Laboratory, which has not been formally accepted by the lab yet,
Yes it has: OAK RIDGE, Tenn., June 12, 2013 — Oak Ridge National Laboratory's Titan supercomputer has completed rigorous acceptance testing to ensure the functionality, performance and stability of the machine, one of the world's most powerful supercomputing systems for open science.
http://ornl.gov/info/press_releases/get_press_release.cfm?ReleaseNumber=mr20130612-00