As a long-time Apple user and security consultant it truly bolsters my confidence in Apple’s ability to cater to the needs of their customers and to deliver a secure and reliable product with each and every release.
The Linux world has been doing this sort of early and often security assessment for many years now with great success. However, amongst security researchers there has been speculation as to the effectiveness of this security testing project. It seems that many analysts are concerned that their work and warnings will not be properly heeded. Only time will tell how much of a difference a pre-release security testing program will make.