Philosophy of default "pkg_add -r" PACKAGESITE?

[Gary Affonso]

Here's one thing I've never quite understood about FreeBSD and I was
hoping somebody could provide some enlightenment...

I've got 6.2-release installed.

By default (as you all probably know) "pkg_add -r" fetches packages from
the "release" directory:

   ftp://ftp.freebsd.org/pub/FreeBSD/ports/i386/packages-6.2-release

Now here's where it gets weird for me.  If I understand the FreeBSD
release methodology , that "release" is a frozen-in-time snapshot of a
particular release (6.2 in my case) that gets no future updates.  As we
move farther and farther beyond a particular releases debut-date, that
snapshot (and the packages it contains) gets increasingly stale.

Do I have that right?

If I do, it seems to me that the absolute first thing I should do after
installing a release version would be to change where "pkg_add -r" is
sourcing packages from.  Either to "current" if I like to live on the 
edge or "stable" if I want to be a more conservative.

I'm curious, why does "pkg_add -r" point to the "release" snapshot of 
ports by default?  Is the idea that a "release" is well-tested and that 
any deviation from that (even security or bug-fix changes) is an unknown 
that new users need to be shielded against when grabbing packages with 
"pkg_add -r"?  Seems to me it would be better to have "pkg_add -r" point 
to stable (which, if I understand things correctly, does get updated 
packages).

And how does one go about *permanently* changing the "pkg_add -r" 
target.  You can set the PACKAGESITE variable in the shell which will 
work on a user-by-user basis but isn't there a way to centrally change 
PACKAGESITE without relying on each user to have properly config'd their 
individual shells?

I know a lot of thought has gone into the current system so I'm thinking 
that these questions are due to the fact that I'm just not grok'ing 
something important about the philosophy behind all this.

Any help would be greatly appreciated.

- Gary