Only UHCI and OCI support is implemented. This reduces the data transfer speed to USB 1.1. Soon there will be a version for USB 2.0 and then high speed data transfer is possible. See Bootmanager Status for the latest news.
Only a small part of EHCI is implemented. This part is used to activate the built in UHCI or OHCI controller.
Only USB mass storage devices are supported. And this is limited to only harddisk and sticks are supported. There is no support for USB floppys or CDROM drives implemented.
There is no USB HUB implementation. Its required to connect your USB device directly to the USB port of your computer.
The USB implementation works on many computers. If it does not work on yours, please contact me. Maybe we can fix it.