If there's no way to disable this randomised MAC stuff, then no iOS 8 device is going to be able to connect to my network at home, or my corporate network at work.
It also means that networks which rely on MAC for authentication (such as the WiFi on the underground here in London) won't work.
Bit silly if you ask me. I'm not sure how a randomised MAC address helps improve security in any way.
If nothing else, it will help encourage the industry from NOT using a MAC address for anything having to do with security or authentication. MAC addresses are too easily spoofed.