I've updated the sparc binary snapshot in `ftp.netbsd.org:pub/NetBSD/arch'.
It's based on -curent source of around April 29.

The format is the same as a standard distribution, including a miniroot
filesystem with install & update scripts. Of course, you can also
unpack the tar files manually, or just try the GENERIC_SCSI3 kernel.

Good luck,

-pk