Firewire is still very popular in amateur and professional audio and video circles. Just read the blogs comparing USB 2 and Firewire and you'll see how heated the conversations can become. The pro-Firewire camp purports it delivers lower "drop frames" and that Firewire has a dedicated processing chip that reduces stress on the main CPU, all allegedly leading to a purer, more complete data transfer. On the other side, the pro-USB 2 camp states lower hardware costs, faster CPUs and less niggly connectors just don’t make that marginal and mostly indiscernible increase in quality worth the trouble.
With USB 3 becoming mainstream we are likely to see a flood of new audio and video interfaces. Intel for one recently promised better operating system and chip integration for USB 3 in Windows 8. Although non-support for Firewire will not mean the automatic death of Firewire (due to third party drivers, ect.) it will likely become a smaller and smaller niche market and probably bid us Farewell in the near future.