Your lack of Ubuntu knowledge is pegging you as a Shuttleworth Cult Member.
"...There are quite a few alternative flavours to the main Ubuntu: the Xfce-based, Xubuntu, the KDE-based Kubuntu,..."
Since WHEN, in the last three years or more, has Canonical and Mark Shuttleworth produced a Linux distribution called Kubuntu?
Shutlleworth decided more than three years ago to abandon the KDE version of Ubuntu, and fired the one man (he had ONE WHOLE PERSON!) dedicated to the entire (then-Canonical) Kubuntu effort: development, maintenance, bug-fixing, improvement...
Got that? Shuttleworth fired the one person responsible for Kubuntu, and abandoned Kubuntu. Period.
The sole development and maintenance of Kubuntu was picked up by a company named Blue Systems, and--according to all accounts--has done one OUTSTANDING job of creating and maintaining what some claim to be the best of the KDE distributions, bar none. Once again, that's BLUE SYSTEMS, folks (it is VERY interesting to discover that when people (commenters to articles) started pointing out that Kubuntu is NOT a Canonical product, file photos from 2006--THAT'S 2006, MIND YOU!!--showing Mark Shuttleworth sporting a Kubuntu tee shirt--and requisite 'rock-star headgear' started showing up in articles on Canonical...articles which have absolutely NOTHING to do with Kubuntu, and articles which have been written in the last six to nine months. Canonical's crap machine does nothing if not churn out crap exceedingly well).
Of COURSE Mark Shuttleworth wants credit for this Kubuntu effort, and will NEVER admit that Kubuntu is NOT A CANONICAL PRODUCT. Go ahead. Ask him. Ask Ubuntu for help with some ginned-up problem you're having with "...the very latest version of Kubuntu...". We'll all be waiting.
Oh, and by the way, Register: You, as a supposed leader in the world of all things technical, pull another boner like this, and you're toast.
I hope I'm wrong; I sincerely do. I stay on top of developments in the Linux sphere well, and I do NOT remember having seen any news to the effect that BLUE SYSTEMS gave or sold ownership of Kubuntu back to Canonical. As a matter of fact, I downloaded Kubuntu FROM BLUE SYSTEMS not a month ago, for installation on one of my laptop computers.
The word "Canonical" appears nowhere.
Not to put TOO fine a point on this, Register, I DOWNLOADED KUBUNTU FROM BLUE SYSTEMS, AND DID NOT DOWNLOAD IT FROM CANONICAL. Want me to draw you a picture?
Prove me wrong, Register.
AND, ADVERTISERS: WATCH VERY CLOSELY; YOU'RE GOING TO LEARN SOMETHING.