It doesn't seem to be a problem on -current..  I've had:

sd0	at scsibus0 target 0 lun 0
sd1	at scsibus0 target 1 lun 0
sd2	at scsibus0 target 2 lun 0
sd3	at scsibus0 target 3 lun 0

sd8	at scsibus0 target 8 lun 0
sd9	at scsibus0 target 9 lun 0

in my config file for quite a while and everything's behaving nicely.