I also wanted to follow up with one more detail, since I noticed
after I sent my mail that you weren't getting prompted for a root
device.

"Darrin B.Jewell" <dbj@netbsd.org> writes:
> You can probably tell it to find the kernel from the command line
> with something like:
>   boot hd:,\ofwboot.xcf hd:10,/netbsd
> 
> >From looking at the disklabel you included, your apple UFS partition
> is showing up as wd0b.  Therefore, when it asks you for a root
> partition, tell it that "wd0b".  In order to have it find this
> without you having to manually tell it on every boot, you will have
> to change this line in your kernel config file:
>    config netbsd root on ? type ?
> to something like this:
>    config netbsd root on wd0b type ? dumps on none
> and then recompile your kernel.

If you try to do:
 boot hd:,\ofwboot.xcf hd:10,/netbsd -a

it will probably just land you back in the bootloader prompt,
but if you type 
  hd:10,/netbsd -a
at that prompt, it should come up and prompt for the root device.

As I mentioned, boot arg passing is somewhat broken.

Darrin