Correct, although I would also mention high-end video; probably the killer app for Thunderbolt. As you said, audio interfaces are a big one, particularly at the

Correct, although I would also mention high-end video; probably the killer app for Thunderbolt. As you said, audio interfaces are a big one, particularly at the high-end, where high throughput is desirable but low latency is essential. As for graphics cards; it is really a general expandability solution, which is much simpler for less-technical users than opening up a PC and attempting to install an expansion card. The new Mac Pro design seems to follow this line of thinking. Thunderbolt will always be a more niche market than USB, but I could see it having an even longer life than FireWire (which is still popular for high-end video and audio applications).