1

One of the main reasons I justified keeping the Apply button for, especially for visible settings, was that one might not want to wait for the settings to apply every time they were changed without first seeing a preview. However, in the window decoration picker, the Plasma theme picker, the wallpaper image picker and (I think) the widget theme picker, KDE SC 4.5 has moved to a new layout that shows the preview of the options before you've actually selected them. For this reason, I think it's now more appropriate, at least in some situations, to apply settings without needing the Apply button and thus to remove the Apply button. I certainly think the Apply button can be unnecessary in sections that don't change the system visibly, and thus don't require to re-draw something on the screen, such as mouse behaviour in titlebars, but that it might still apply in certain situations e.g. when changing an application's shortcuts.

Discuss!

If one was to accidentally hit and hold the down arrow, moving the selection, or they cause a click with the touchpad when they really mean to move the cursor, I don't think users will be to happy... The down arrow example could also mean a spike in CPU usage, as it changes the themes 10 times over.

For accidental clicks, I don't think it would be so huge an annoyance, but yes: I'll agree that moving up/down a selection might cause some grief. However, this would only genuinely be a problem if the keyboard was the only method we had of scrolling up/down a view.

Would still like to see some broader discussion, though

This gets brought up occasionally and the KDE developers always say they are absolutely not going to do it.

Ah. It does? They do? :S