In decreasing order of priority:

Bugs:
- Synchronization on driver unload between usbhMainLoop and driver APIs

Enhancements:
- Way to return error from the load() functions in order to stop the enumeration process
- Event sources from the low-level driver, in order to know when to call usbhMainLoop (from the low-level driver and from the HUB driver status callback)
- Possibility of internal main loop
- Linked list for drivers for dynamic registration
- A way to automate matching (similar to linux)
- Hooks to override driver loading and to inform the user of problems