CircleID

The GB code is not removed from 3166. The last change
only states that a remark about GB has changed. To quote: 

Delete the remark "Includes the Channel Islands, the Isle of Man" (p. 20). Delete the entry for the Channel Islands in Annex A (p. 51). Delete the entry for the Isle of Man in Annex A (p.51).

GB is still an Officially assigned code element in the decoding table.

There is a FAQ page about the code list.
The FAQ also tells you the procedure for adding new country names and codes to ISO 3166-1 and why both UK and GB are assigned.

Jaap-

Thank you for the point of clarification.  I have received a few emails from folks making this point to me as well.

On a separate note, one conversation that I had by telephone about this topic mentioned to me that there was a bit of hesitance on the part of the ANSI to approve the official addition of the JE, GG, and IM to the ISO3166-1. 

Apparently there was a concern there about folks just adding these countries to 3166-1 for the sake of getting ccTLDs, but once it was pointed out to them that these had already been in existence for a decade, their resistance crumbled.

-Jothan

Away from the world of domain names, GB is a widely used code still - there are plenty of British cars driving around Europe with GB stickers on.

Ummmm, How often are you asked how to get a ccTLD??  Doesn't seem like something that a lot of folks would be curious about ;-)

Humbly, I must state that I made a factual error in my initial posting with regard to the removal of GB. 

In hastily reading the ISO change order, I made a velocity error and I mis-read it.  GB is not slated to be removed (which I interpreted to be the case from the wording of the form's small print at the bottom); rather, IM, JE, and GG are being created and moved from underneath GB, and GB's record will be modified to no longer reflect those regions. 

So the three are out from under the nest, so to speak.

Edward Phillips> I picked up a couple of those GB stickers when I was in London last year. 

McTim> I get asked at least 4 times a year, typically by someone new to domain names or who recently registered a domain in a country code for the first time and finds out that they all function the same as gTLDs.