Absolutely man. Firewire is being phased out. Can't even find a laptop with them anymore. My new MOBO for the i7 doesn't have one either.
I run an older Tascam US1641 via the USB 3.0 port on my newest desktop. Same when I had the old dual core dell, that I added the PCIe card to. Absolutely no connection problems. The Dell however, did have a buttload of problems regarding bloatware and use of the AMD dual core processor. I finally got it setup to run fairly well, then the hard drive crashed during a session. I vowed to never have that happen again, so I built a monster PC for about $1200, including RAID1 setup, so I don't have to go through the nightmare of installing/registering all my software again. Also added an external audio drive, as well as an addition external to back up the other. Nothing sucks worse than losing files due to a drive crash. Well, maybe not having an interface work properly. :/ That has been easy for me since I figured out the USB communication problem. Even a wireless mouse, can mess with a USB interface connection. USB is pretty much a one purpose gateway, when involving streaming audio. Firewire could candle more at once, but no better as far as quality of signal.
USB 2.0 is where the interface manufacturers are at now. I haven't even heard of a USB 3.0 interface yet. Probably because there isn't a reason for it as of now. 16 individual tracks at once, works perfectly for me at this point. Not sure that USB 2.0 cant handle more. Keep in mind, that USB 1.0 can, as far as I know, only do 2 tracks at once. Sometimes, reviews and conversations about USB, can be confused with the older version.
USB2.0 interface, adequate multi core CPU, a separate audio drive, optimize your PC for recording, and delegated USB controller for the interface, will get you running smooth. On my current system, I can record new tracks, to a 40+ track project, with a buttload of VST's, as well as VSTi's, with less than 8ms of latency, while monitoring from my DAW (Cubase 6). I never have problems anymore. Life is good!