I’m not fully convinced here, but the general talk around in interwebs is that the oversite of leaving vfdecrype key in the unencrypted ramdisk basically means its fair play.  Not sure how that works, but ok.  Still this does not mean we should see a release of Siri for iphone4 anytime soon.  There is still the issue of connecting to the server, although doable, should be pretty easy for Apple to sort and stop with the proper sniffing techniques.

Here is a quote from ijailbreak.com; so make if it what you will.

Apple released a strange tweaked version of the iOS 5.0.1 firmware to developers –  iOS 5.0.1 (build 9A406). At first not much was known about this new firmware version released by Apple, but now we have gotten word from MuscleNerd that it actually includes an unencrypted ramdisk with the vfdecrypt key stored in a plain text file. This essentially means that developers with the right know-how could extract the iPhone 4S iOS 5.0.1 firmware like a .zip file and gain access to its filesystem.