[Glenn Fleishman on changes to ‘Find my iPhone’][1]:
> So even if you wipe your iPhone remotely, you don’t have to worry about anyone else ever being able to use it again. If it’s later recovered, you can easily restore from your most recent backup, entering your Apple ID and password when prompted.
Read his entire post, some really great security changes for iPhone users. It seems pretty clear to me that Apple is serious about helping users secure their devices (at least from non-NSA types — I can’t speak to what they are doing on the NSA front).
[1]: http://tidbits.com/article/14113