A
preliminary inspection indicates that most of the required pieces fall
under the old BSD license, with a few under the revised BSD license or
the GNU GPL. The majority of these have copyrights by either UCB or The
NetBSD Foundation, Inc. (TNF)
If the copyright is UCB, you can change the license. UCB already said
so. If the copyright is TNF, you can't.
I suggest you get these programs from FreeBSD instead of from NetBSD.
The FreeBSD people did make that license change.
Is it the intent of the GPL, as it currently stands, that this situation
(system libraries which are under a 4-clause/old BSD license) should
permit binaries licensed under it to link against those system libraries,
when the system libraries are distributed as part of one package, and the
GPL-licensed binaries as part of a separate package?
When they are distributed separately, that is clearly permitted. GPL
version 2 does not permit distributing them together, but we have
always treated this as ok in the normal cases. In fact, I am trying
to rewrite the so-called "system library" exception for GPL 3
so that this is clearly permitted in the cases that are harmless.
