EPSON Perfection series is the fastest damn USB scanner I've ever seen, since it has a very good internal buffer and does all optical conversions in hardware. The quality is terrific, and they are all good with dust, too.
I have the 1640su, and it can do full-sized, 24-bit color, 300DPI in about 10 seconds. Just make sure you plug it into a USB root. From a hub, it tends to lock-up, like many other "high-speed" USB 1.1 devices, like cameras and printers.
Of course, my scanner is 3+ years old. The new ones are based on USB 2.0. The evolutionary model of mine is the 3170,
found here.
I only use TWAIN for scanning, but EPSON is known for good software bundles, which includes Photoshop Elements, which supposedly comes with good direct-to-web and thumbnail gallery capabilites.
As for resolution and 48-bit, those are just marketting terms and software gimicks that mean nothing, so every scanner has them. Draft quality alone on the Perfection is pretty damn good, IMO. I swear by it.