A new big change is being discussed on the Ayatana mailing list: single click for opening files and folders in Ubuntu (not Kubuntu - which already uses single click for opening files and folders). In fact there are 2 separate threads: one about defaulting to single click for opening file and folders and another to use a single-click mode for all GNOME applications - but only the first one seems to be seriously taken into consideration. The rationale behind this is:
Double-clicking is a noteworthy hurdle when learning to use the mouse. For some users, it stays a challenge and can be impossible in case of certain impairments. It can hurt if you have RSI, and if you haven't already, it makes it more likely you develop some.
Often overlooked because so many people know about it already, but the need for double-clicking to trigger specific actions is actually hard to discover.
Common anecdotes about users who default to double-clicking even in web browsers are a hint that users do not necessarily differentiate between links and icons on the desktop or in file managers.
You can read the whole discussion, HERE. Some more info @ Ubuntu Wiki.
It seems Ubuntu is trying to change the game, but is it trying too much? It would be really interesting to hear the users' opinion on this so let us know what you think in the comments!
Image credits: Diego Moya