There is something else...even USB3.0 devices run faster on USB2.0 than USB2.0 devices themselves (though not by much) due to the more powerful controllers found in USB3.0 devices. Add to that the fact that USB3.0 is full-duplex (meaning you can transfer data both ways simultaneously, very important for external HDDs), and that it can theoretically reach 4.8gbit/s speeds (let's assume half of that, as with USB2.0, we would get 300MB/s). And now, external SSDs are indeed possible. With 128GB and 256GB SSDs getting cheaper, and 512GB being readily introduced, I believe we are at a very important turning point with external storage. No more waiting for files like before.
xterm, check out the 128GB Magnum USB flash drive. And tell me what you think.
@solo220: Yes, if you mean the USB flash drive, yes it's available. Along with others like the Transcend Transflash USB flash drives, which are also USB3.0, and I'm guessing several others too.
http://www.pcandparts.com is where I can find such USB flash drives. I have the 16GB Transcend Transflash and I am very satisfied with its performance. Rated at 70MB/s read and 20MB/s write. Somewhat achieves those (especially the read). With write, you have to have contiguous files. Else transfer rates with suffer, which is a characteristic of all flash technology nowadays.