Are there any USB 2 peripherals out now, with Mac drivers? That would be the next headache. Apple has put a lot of work into USB audio, HID and USB mass storage support. Embracing 2.0 means redoing all of this, while realizing that they're possibly hurting FireWire's positioning. Fat chance. 1.1 has a place, 2.0 doesn't.
This is one reason why I'm not buying an iMac. And if 2.0 does become a player in the Mac arena, I'll just buy a card for my G4.