in true "blogs are the new mailing list for odd conversations" fashion, clarence wrote a response to my response to his blog about the new toolbar default in kde4. (random thought: is there an agregator that uses trackbacks or other such metadata to thread blogs into conversations?)
i like clarence's new 6 element toolbar for kde4. it's much more task appropriate and easier to manage. he does bring up two issues that i agree are valid to talk about: system wide merging messing up toolbars and icons under text adding to visual clutter.
in kde3 we have a system wide file that defines standard toolbars. the problem is that toolbars simply aren't standardizable in the same way that menubar layouts are in my opinion. toolbars simply don't cope with the odd "accidental" entry as they are way too "in the face" of the user. perhaps in kde4 we shouldn't define a default toolbar at all and make it opt-in per-application so that we get task appropriate toolbars. the number of apps that don't use the system definition with noMerge is already pretty high anyways.
as for text adding visual clutter, if we use a nice (e.g. smaller) font for it it really doesn't get in the way. i've been using toolbars with text under the icons since 3.5 was released (to get some first hand experience with it in prep for kde4) and the problems are long names and big font sizes. they help disambiguate toolbar icons quite nicely so i don't have to learn every single app inside and out. and in clarence's screenshot it's obvious that sometimes it even shows contextual information, as can be seen in the "Undo: Line" button.