Since Firefox is software which is installed on my computer, I rest my
case. Yep -- I would find it screwy if the Firefox auto-update told me
about a new version of Windows, or even of Thunderbird.

different

What Mozilla internaly considers them is irrelevant to the end user. The
end user sees "Firefox version whatever". None of this is making any
sense, anyway -- they could as well consider Firefox 1.4 and 1.5
"different products", or even 2.0 and 2.0.0.1 "different products".
That's just word-games.

That is illogical; 2.0 is a straight upgrade rather than a sidegrade.
Firefox 1.5 is not to 2.0 as it is to Opera, or IE, which is what you
seem to be claiming.

What "people"? There's a good reason why wikipedia would flag your
article with "This article contains weasel words" if you'd written this
there, you know...

That's largely because Vista isn't free. It's also not true anyway. I
just did some research, and Windows Update did something suspiciously
like what you are describing a few months back, when the big "Vista is
coming!" MS hype machine was in full bore.

First, it pushed people to install "Windows genuine advantage" with the
threat to withhold updates if it wasn't installed, or reported your copy
of windows was phony.

Next, it pushed people to install "Windows genuine advantage
notification", which would supposedly make the former tell the *user*
and not just Microsoft if it thought their windows were phony.

In actual fact, the "notification" thing had all kinds of side effects
and some sort of legal crud telling people they weren't permitted to
remove it once they'd installed it. One of the commonest side effects
was that WGA would "suddenly realize" that their copy was bogus. This
would stop updates being available to the user, but worse, it would
often force them to actually redo the "product activation", whereupon MS
would frequently refuse to cooperate on the grounds that their windows
copy was supposedly bogus. This often happened to people who had gotten
preloaded machines with Windows on and hadn't done any funny business.
It also did not happen to people who only installed the first of the two
"genuine advantage" thingies.

Moreover, the "notification" thing was NOT necessary to continue to
receive updates. Also, both were pushed as "critical" updates by Windows
Update, as if they were security patches to protect users from being
hacked. They weren't -- in fact, the "notifications" one, at least,
actually made users have *less* control over their machines, so if
anything there should have been a "critical update" to *remove* the
"notifications" update; I think I'd have recommended including it in the
next "malicious software removal tool" myself.

I found posts on multiple software-pundit, product-gripe, and similar
blogs all speculating that the real motive behind these bogus "critical
security fix" updates wasn't users' security, or even (a false sense of)
security for Microsoft's so-called "intellectual property", but in fact
to push people towards Vista. The "notifications" update created the
ability to remotely deactivate already-activated copies of Windows XP,
which otherwise would work until people changed their hardware sufficiently.

Apparently, Microsoft found the two or three year average replacement
time for peoples' PCs to be too slow and impatiently figured out a way
to force people to replace XP sooner than that, leveraging the existing
product activation.

It backfired. There was so much bad press that MS yanked most of the
"notifications" misfeatures in a later update and quit peddling it, and
decided to let people who were happy with their XP keep it until they
have new hardware after all.

But there is one way in which you are technically correct. The updates
didn't themselves explicitly push Vista. Although making XP stop working
and leaving users with no recourse except to buy a new copy of Windows,
even while XP is being swept off the shelves and Vista boxes lined up by
their hundreds, amounts to the same thing. Well, worse, actually.
Nagging about an update is common practise. The kind of arm-twisting
observed here is the special province of Microsoft, governments, and the
mob, as near as I can make out. :P