Nö, die Amis habens auch:
http://www.youtube.com/watch?v=g-4gwZZ6I94
und hier:
I've got the exact same problem. After installing the new USB Apple Keyboard, I lost the ability to use the option/alt key to select my boot partition when starting the computer.
I've been forced to change the startup disk choice from within the operating system.
For those who need to know the work-around, you can go to the System Preference on the Mac and then choose "Startup Disk". In the new window, highlight the Windows partition then click the restart button.
In Windows, you have to go to the Control Panel and choose "Bootcamp". Then highlight the Mac OS X partition and click the restart button there.
While this works, it is not nearly as convenient as using the alt key. If anyone has figured out a way to make your selection during the boot process, please share.