Yes:
ok probe-scsi
Target 0
  Unit 0   Disk     UNISYS  U1545 ST12550N  280900460958Copyright (c) 1994 Seagate All rights reserved 0000
Target 6
  Unit 0   Removable Read Only device     DEC     RRD42   (C) DEC 1.4a
I made sure to put the root partition in the first 1GB of the disk (it's 128MB) so there shouldn't be any problems there.
 
As a quick workaround you should be able to boot the cdrom kernel with
-a and then give sd0a as the root filesystem.
This still isn't working.  I get the prompt for what filesystem to boot from, but various combinations of sd(0,0,n)netbsd don't work.  When I boot the installer and drop to a shell, I can mount /dev/sd0a and see that there is a valid kernel named netbsd.  I'm at a loss as to what is going on here