Oddly enough on the PC side, this has been worked around in software and the BIOS of a machine, and not by an ATA 133 controller. I wonder why Apple has not done the same, it's a simple change.
In fact, all WD drives are still ATA 100, even above 128gb. ATA 133 was a marketing ploy by Maxtor.
Another case in point, my empeg worked around it by a simple tweak to the IDE driver in the kernel. It's a Linux based MP3 player.
Maybe Panther will address this.