Tonight when I plugged my iPhone in, iTunes informed me that an update, version 1.0.1, for the iPhone was available. iTunes reports that the update is just for "bug fixes" with no other information on what might be included. The update took about 5 minutes to load and went smoothly for me.
Some folks have reported that the update crashed and they had to do a complete restore and then resync. That significantly increases the time to update. This is apparently true for anyone who's used iFuntastic to mod their iPhone. There are also reports that the update "breaks" hack for things like third party ringtones.
Rumors of the update have been running around the Web since a security flaw in the iPhone was discovered last week. The details were set to be revealed at this week's Black Hat 2007 conference. While the update doesn't claim to be a security update, I suspect Apple patched the hole while they were at it.
Apple also released updates for Safari 3 for both the Windows and the Mac. Both version install security updates and the Windows update promises "improved stability."