Jeremy,
As Shawn said, it has been in use in a limited way for some time especially for Avionics (see the sticky about SITS testing). Only recently has the concept been expanded to cover all aspects of testing and, much more to the point, had buy-in from the certification authorities. I'm not so sure, for commercial transports at least, if you could get away with not flight testing a particular configuration - it's a requirement for AFCS under AC25-1329.
A certain Canadian manufacturer is currently using ARP 4754 for its latest transport - how "successful" this will be remains to be seen.
Last edited by ICT_SLB; 6th Jan 2013 at 02:56.