The presence of tooltip text message should not be time-dependent (4-6 seconds) but rather mouse-cursor-hovering-dependent. As long as the user has mouse cursor hovered over an icon, its correspondent, associated tooltip text message should be viewable, visible, present and readable.

This bug report is not necessarly related to system tray.

I chose "desktop" as component but I am not sure if this is correct. Please change this if you know what would be the correct component for this bug report.

Reproducible: Always

Steps to Reproduce:
Hover mouse over an application present in systray icon (say Klipper icon, Network interface icon, etc). 

Nota bene: this bug report applies to a lot of hovering-icons situations and not just to systray icon.

Actual Results:  
The tooltip will remain visible, readable for 4-6 seconds.

Expected Results:  
The tooltip should remain visible, readable for as long as the mouse cursor hovers over the application icon.

This bug is definitely an accessibility and usability matter.

If a brand new user is only given 4-6 seconds to read 6 or more words in a tooltip message, then (s)he will most likely have to hover mouse over again the icon to read the tooltip text message. This can be annoying, furthermore frustrating if/when a "fugitive" tooltip message only appears once.

I noticed this time-dependence of tooltip almost everywhere in KDE and, after searching a lot in various settings, preferences, customizations, KDE configurations, I could not find where to increase tooltip message visibility duration or how to increase tooltip message visibility duration.

Note that some softwares have settings, configurations allowing the user to set tooltip duration: 
1- eg. LibreOffice 3.6.2.2.
2- If I hover the mouse cursor over an widget in the plasma/add widget (green "+"), the info-balloon tooltip text message will remain visible, readable, viewable as long as the mouse cursor is over such widget.

I am using 
Linux 3.5.0-26-generic i686 (32bits) 
Qt : 4.8.3 
KDE Development Platform: 4.10.1
Kubuntu 12.10