Use "samehost" by default in pg_hba.conf?

Now that the samehost/samenet patch is in, I wonder if it wouldn't be
a good idea to replace this part of the default pg_hba.conf file:

# IPv4 local connections:
host    all         all         127.0.0.1/32          @authmethod@
# IPv6 local connections:
host    all         all         ::1/128               @authmethod@

with:

# local connections via TCP/IP:
host    all         all         samehost              @authmethod@

The advantage of this is that connections made with "-h machine_name"
instead of "-h localhost" would work without customization.  I can't
see any disadvantage to it.  Making the change now would also give
us an opportunity to test the samehost/samenet implementation in the
buildfarm, at least for machines without Unix sockets.

(Note that you would still need a non-default setting of
listen_addresses for "-h machine_name" to actually work.)

Comments?
        regards, tom lane