Anyone who says its obsolete, or that USB Audio Interfaces use USB now, obviously have no idea what they are talking about. How many people use Pro Tools and have Digidesign interface?
And how about the audio interface that was designed for mac, that they actually sell in the apple store, the apogee duet. It runs off of firewire 400. Its a pretty new piece of hardware! I need two usb ports for this, i run off an external hard drive for audio recording with the firewire 800 port. As well i record with the apogee duet which uses firewire 400.
Almost every musician I know, and all media users, use firewire ports.