In case you didn't see it:
Media Alert
Apple Announces Ultracompact USB Adapter Exchange Program
CUPERTINO, California-September 19, 2008-Apple today announced that
under certain conditions the new ultracompact Apple USB power
adapter's metal prongs can break off and remain in a power outlet,
creating the risk of electric shock.
Apple has received reports of detached prongs involving a very small
percentage of the adapters sold, but no injuries have been reported.
Customer safety is always Apple's top priority so it has voluntarily
decided to exchange every ultracompact power adapter for a new
redesigned adapter, free of charge. For more details on the exchange
program please visit
http://www.apple.com/support/usbadapter/exchangeprogram/ .