Read [1], [2], [3], [4], [5], [6] and [7], report what is notable.
Add more sources (even without adding any text) for the fact that 12.04 got good reviews. http://www.zdnet.com/blog/open-source/ubuntu-12-04-arrives-and-its-great/10836fs
From [8], regarding 13.04: "the promised improvements in privacy controls for the Dash search-and-launch tool did not get included in this release; users are still faced with an all-or-nothing choice when it comes to including internet results in searches."
From Mir talk:
The ref cited above indicates that the reasons were, as Canonical says: "we are aiming for a more extensible input event handling that takes future developments like 3D input devices (e.g. Leap Motion) into account" and "With respect to mobile use-cases, we think that the handling of input methods should be reflected in the display server protocol, too. As another example, we consider the shell integration parts of the protocol as privileged and we'd rather avoid having any sort of shell behavior defined in the client facing protocol" as well as "we decided to go for the following architecture w.r.t. to protocol-integration: A protocol-agnostic inner core that is extremely well-defined, well-tested and portable. An outer-shell together with a frontend-firewall that allow us to port our display server to arbitrary graphics stacks and bind it to multiple protocols." So there is a bit more to it than that. This should probably be added into the article.
Possible sources for Ubuntu_(operating_system):
http://arstechnica.com/information-technology/2012/12/shuttleworth-ubuntus-goal-is-one-os-from-phones-to-supercomputers/ "While Ubuntu is the most widely used Linux desktop"
Lista das official derivatives: http://www.ubuntu.com/project/about-ubuntu/derivatives
http://arstechnica.com/gaming/2012/07/valve-announces-ubuntu-port-of-steam-source-engine-and-left-4-dead-2/ EA e Valve suportam Ubuntu
http://www.pcworld.com/businesscenter/article/230878/has_unity_knocked_ubuntu_off_its_pedestal.html
http://www.linuxinsider.com/story/76556.html
"Index of /". Retrieved 13 July 2012.
Larabel, Michael (13 July 2012). "Debian Wants To Work With Its Offspring (Ubuntu)". Phoronix. Retrieved 13 July 2012.
""Ubuntu Development Team" team". Retrieved 13 July 2012.
"UbuntuDevelopment - Ubuntu Wiki". 4 May 2012. Retrieved 13 July 2012.