I've seen a number of somewhat odd things in the depths of the cardbus
code; I'd be greatly interested to hear from those who know what they're
doing (unlike me.)

It appears that '#if rbus' is sprinkled liberally throughout the code -
but AFAICT that's never been set to 0. Is there any reason to keep those
includes around?

How similar are cardbus 5.0+ cards to pci? Many of the vars in
sys/dev/cardbus/cardbusvar.h look identical to those in pcivar.h;
it'd be quite nice (for porting purposes) if some of them could
be changed from cardbusreg_t to pcireg_t, if they are in fact the
same kind of values.
 
On a related topic: I've heard that there were plans afoot some time
ago to merge cardbus with pci; what technical issues remain preventing
that from happening? (modulo Copious Spare Time)