Feel free to correct me if I am wrong in the above that is just from what I have read.
I've used both Arch and wheezy.
It's a hardware thing, the foundation chose to use the BCM2835 chip in order to keep the raspberry pi under $35.
One link of many, the only forum I've found that claims they get USB3 devices to work with raspberry pi is this one.
http://www.raspberrypi.org/phpBB3/viewtopic.php?f=7&t=1147I stand corrected then I just thought I had seen Kano post that he was using a USB 3.0 hub with minepeon.