Hello,
tried to play with dcons_crom a bit. I'm not sure 
bus_generic_identify_sameunit() is apropriate for it; the parent device (the 
bus is always in state DS_ATTACHED so bus_generic_identify_sameunit() returns 
without doing anything. Using a dcons_crom_identify() that unconditionally 
does  a BUS_ADD_CHILD() (similar to the one removed in r1.3 of dcons_crom.c) 
allows me to use dcons_crom as expected. Don't know if this is the correct 
fix though...

Aggelos