One of the reasons I photograph many prints and documents with a DSLR - not even a full frame one, but an APS-C or even m4/3 DSLR captures files instantaneously, and saves them to the memory card for later transfer to a computer, and delivers a 20-25 Mbit Raw file that offers a fair amount of editing ability in LR.
Once my camera is on a tripod and my lighting set up, I can shoot frames pretty quickly. The exposure doesn't really change, nor does the color balance. I can alter the size of print I am shooting by rasing or lowering the print on a stack of large books, so I can switch between 2x3 inch prints to 8x11 inch prints pretty quickly. Raising or lowering the print is easier and faster than changing the camera height on a tripod. I use a 50mm Macro lens so it has a nice flat field, focuses closely enough, and is small and light. I use a cable release to minimize any vibrations. And I get better RAW files, faster and easier than with my flat bed scanner.
I spent a few moments looking through film scanners on B&H, and I can't find one that uses a faster computer connection than USB 2.0. I didn't see one.
The truth is that the time is spent in aquiring the scan data, the transfer of the data to the computer is really not the limiting factor for a 20 or 30 Mbit file, even on USB 2.0
What is really needed is a first class proconsumer film scanner for 35mm film, that is fast scanning and of high optical quality, but there seems to be a very limited market for these devices any more. I see lots of cheap ones that are of no interest to me.
For many folks, Chris's suggestion of a scanning service makes a lot of sense - it requires a modicum of high quality equipment, and a fair understanding of image editing to do well. And can be time consuming.
I do much of mine in the cold of winter when the snow is blowing about....