The feature is still draft and only made version 1 in June 2009 (http://xmpp.org/extensions/xep-0166.html). I don't actually track changes in XMPP so I am open to correction on this point.

Around the time I actually wrote the article (many months before it was originally published in .net magazine) there had just been a libjingle release and I was told at the time it was a new thing to have this available to 3rd party developers.

libjingle has been around for years; Wikipedia says December 2005.

(It doesn't matter, but I also raised an eyebrow and started looking for the date on the blog entry when I read that sentence.)

Also, GTalk does not use libjingle but its own slightly-different pre-standard implementation, that's why it is impossible to talk to GTalk users with a XMPP client that supports Jingle via libjingle.

This is quite a mess.

I have updated the article to reflect that this was not a very recent addition.

Wikipedia may say 2005 but it did not make the draft status that the article refers to until June 2009, which we can all agree is a lot more recent.