Well its happened.
Apple held their press conference yesterday (16th July 2010), in response to news of the iPhone 4, droping its bars (Was it not a BAR that they lost the iPhone in, in the first place).
Basicly anyone that has brought the device and uptill the 30th September 2010, will be able to claim a free bumper or a case. Apple are not able to make enough of them in time, so selected 3rd party cases will be offered, via Apple’s website.
You can see the press conference that Apple held about the issue with the antenna here
and examples of the same happening to other makes of smartphones