In BETA5, here is the output of "find . -perm -4000 | xargs ls -l"
in /usr/lib/amanda
.
-rwsr-x---    1 root     disk        11087 Jul 18 21:56 ./calcsize
-rwsr-x---    1 root     root        30518 Jul 18 21:56 ./dumper
-rwsr-x---    1 root     disk         8411 Jul 18 21:56 ./killpgrp
-rwsr-x---    1 root     root        30649 Jul 18 21:56 ./planner
-rwsr-x---    1 root     disk         6172 Jul 18 21:56 ./rundump
-rwsr-x---    1 root     disk         7488 Jul 18 21:56 ./runtar

I am completely guessing, but shouldn't "dumper" and "planner" be group
disk too?

We've had a couple of gid==0 leaks in the past. We don't really want such a
leak to give access to more suid-root binaries.
Note that if you have group disk, you gain nothing by having access to a
few suid-root executables. If you have group disk, you can modify arbitrary
block devices anyway.