This is very good news for those of us in the Mac community that have been pining after some of the high-performance RAID systems available on other platforms. For a long time, 3ware has been a vendor of choice for hardware RAID in both the SATA and ATA arenas due to their reliability, reasonable pricing, and wide OS support. In particular, support for FreeBSD has made these folks the belle of the ball for many UNIX installations. But, the Mac was left out.
The bundle (SATA RAID card, external enclosure attached by SATA-ML cable, and drivers) is supposed to be shipping through distribution and direct retail this month.
The press release talks about the G5 in particular and PCI Express, so certainly only the latest generation machines will be supported, and there's no indication (yet) of Intel support.
Perhaps the best news is that this product includes (according to the data sheet) the 9590SE-4ME, a 4-port version of the company's top-of-the-line product.