Imagine a car company with a successful line of sports cars. One day it decides to introduce a new model with new, clean lines and all the latest bells and whistles. Only one catch: the new model is available only with a 120 horsepower four-cylinder engine.
This is essentially the situation with Mac OS X Snow Leopard, which comes without support for the SiI3132 chipset, the most common chipset used in external SATA disk controllers. ESata is the 8-cylinder turbocharged engine of disk interfaces, the de facto standard for anyone for whom performance matters. And that includes anyone doing serious video editing, which is one of Apple's specific target markets.
Of course, it's not completely surprising that Apple would punt on ESata, since it already released its latest MacBook "Pro" models without an ExpressCard slot (except for the 17-inch model), which was the only way to get an ESata interface. All this leaves me at a loss. Does Apple intend for people to use MacBook Pros to edit video or not? And if not, what exactly is their target market? I don't get it.
Happily, through the grapevine I heard that the Silicon Image 3132r5 driver might work with Snow Leopard. I tried it, and it does indeed seem to work. I have not tested it extensively yet (I don't trust it with my live data so I need to swap an older drive into one of my Sata enclosures) but it looks very promising.
If anyone else decides to try this please let me know if it works for you.