There's been some discussion about the possibility of USB 2.0 audio/MIDI interfaces in the future for use with the Mac. This may be old news to some, new news to others, but according to a blurb on one of the Apple pages, Sonnet has a PCI card that sports connectors for ATA/133, Firewire, and USB 2.0 (backwards compatible with 1.1). You can find the link by scrolling down on this page:
http://guide.apple.com/index.lasso
At $179, it's supposed to work with 9.0 through X. In addition to 2 usb 1.1/2.0 ports and 2 Firewire ports, it supports up to 4 internal ultra ATA drives, so it might also offer some options to some of you considering recording drive purchases.
Hope this helps.