EvertVd - 9:51 pm on Feb 24, 2012 (gmt 0)
Thanks for the 'bump', I wanted to reply to my own question but hadn't had the time yet.
I managed to find a (I think rather obscure) note in the aria practices document (http://www.w3.org/TR/wai-aria-practices/#relations_labeling) which states:
It should be noted that (X)HTML provides a <label for> element which you can use to label form controls. For all visual objects, including (X)HTML form elements, you should use the WAI-ARIA aria-labelledby property for labeling.
So if I understand this correctly, aria-labelledby should be used for all INPUT-elements?
What this does not say however is if this makes the for-attribute redundant? WCAG places some heavy emphasis on the for-attribute so I guess we need to use both? Unless I completely misunderstand this note.