It is official in the sense that Ubuntu recommends it. So it has their
blessing otherwise they would not feature it on their website, but they have
no control over it and accept no responsibility.

Canonical is a corporation and has to act responsibly. However, the law is
uneven and this is important. What is legal in one country may not be legal
in another. Some countries do not honour software patents at all while
others such as the US are leading the push for them. Users in those
countries wonder what all the fuss is about. The irony is that it is often
American users who are the first to complain about codecs and drivers not
being easily accessible. Maybe they should complain to their government
instead of to Canonical.

Having the restricted extras is a way of leaving it up to the user to decide
what is legal and ethical for them. Medibuntu is similar, but has a somewhat
different approach. Canonical is supporting where it can free alternatives
like Fluendo and Gnash, but Medibuntu goes back to the real thing. The
codecs in the Win32 and Win64 packages are the same as you would get in
Windows. Medibuntu also includes GoogleEarth which Canonical does not.

As for support, Medibuntu does support it and you will get upgrades as long
as you have added the Medibuntu repositories. Nothing from Medibuntu passes
through Canonical servers, so you could say that they do not support it, but
it is supported by Medibuntu itself which offers upgrades.

The goals of Medibuntu are theirs and the goals of Canonical are their own.
I am not sure how much intersection there is with separate projects. From a
users point of view they can install both or neither depending on their own
position on such matters.

Maverick offers for the first time the opportunity to install the restricted
extras at the time of installation. You just need to check a box. You can
also check a box to go the opposite direction and only get free and open
software. Many Linux advocates will choose this option as they believe that
all software should be without restriction. It takes all kinds you see.

I have never been a fan of the Mint approach and I am not sure that the
approach in Maverick is a step forward for Linux. But many users will
welcome the convenience, but convenience is not always in our best interest.
The easy road has been a path to destruction for many people over the years.

[As I write this Microsoft is working with US legislators and ACTA to push
software patents on the rest of the world, but at the same time trying to
get courts to quash software patents that have worked against them, as is
the case with XML patent infringement in Word. They also are suing Motorola
and Google over Android's use of syncing with Microsoft file systems. It is
the old case of if I do it then it is okay, but if someone else does it then
it is wrong. The whole notion of patents is so fraught with difficulty that
it makes a mockery of itself. If you understand this issue then you know
more than I do.]