According to Apple Insider, sources using the latest iPhone firmware claim that the firmware was recently updated with additional security features.
It seems that Apple "responded to concerns over the integrity of the iPhone’s data reset methods, Apple has taken the extra step and built a more secure data wipe function into the next version of the handset’s software", AppleInsider has learned.
While the original iPhone firmware has an "Erase All Contents and Settings" option, we’ve all found out that this only does a regular deletion of the information stores on the device.
In the 2.0 firmware, however, the option will mimic "Secure Empty Trash" deletion in Mac OS X.
While original deletion simply erased the file, 2.0’s secure erase will delete the file, unlink them, and overwrites the affected memory sectors several times.
The downside, however, is the estimated 1 hour it takes to complete. Perhaps this is a small addition to make the iPhone more enterprise friendly.