SATA and port multiplication

SATA hard drives and hard drive enclosures are evolving rapidly to become ever more useful.  With its outstanding bandwidth of 3.0 gigabits/sec, SATA II is spawning some interesting storage products, including cards and enclosures with port multiplication.  I came across an explanatory article today which will be helpful to anyone considering high-capacity external storage: Serial ATA Port Multiplier Technology.

Any external storage unit I purchase will use port multiplication—I want one enclosure and one cable, with the ability to hook up more enclosures without having to buy more PCI cards—port multiplication allows that, all with outstanding performance.  With Firewire a dead technology, can motherboard support be far behind?