When I am asked to work on someone's computer, due to slowness or other issues, I often set it to show all notification icons. Then I go through each program and ask the user if they need program XYZ or not, and often their answer is "I don't know what that program does, and I don't use it". So I uninstall it.
Showing all icons all the time has the terrific side-effect of reminding people to clean up junk that they don't need.
Also, I am surprised that more people don't use a two-row-high taskbar. You get the added benefit of date and "day of the week" below the clock, along with allowing all notification icons to be shown without taking up so much of the taskbar.
