AS DrageMester pointed out.
The throughput numbers would lead you to believe that USB 2.0 provides better performance. But, differences in the architecture of the two interfaces have a huge impact on the actual sustained "real world" throughput. And for those seeking high-performance, sustained throughput is what it's all about (reading and writing files to an external hard drive for example).
Architecture - FireWire vs. USB 2.0
FireWire, built from the ground up for speed, uses a "Peer-to-Peer" architecture in which the peripherals are intelligent and can negotiate bus conflicts to determine which device can best control a data transfer.
USB 2.0 uses a "Master-Slave" architecture in which the computer handles all arbitration functions and dictates data flow to, from and between the attached peripherals (adding additional system overhead and resulting in slower, less-efficient data flow control)
Performance Comparison - FireWire vs. USB 2.0
Read and write tests to the same IDE hard drive connected using FireWire and then USB 2.0 show:
5000 files (300 MB total) FireWire was 33% faster than USB 2.0
160 files (650MB total) FireWire was 70% faster than USB 2.0
5000 files (300 MB total) FireWire was 16% faster than USB 2.0
160 files (650MB total) FireWire was 48% faster than USB 2.0
As the performance comparison shown above confirms, FireWire remains the performance leader. And is the best choice for DV camcorders, digital audio and video devices, external hard drives, high-performance DVD burners and any other device that demands continuous high performance throughput.