Has global armor absorbtion changed?

Search was worthless on this...

Does anyone know for sure if the damage absorbtion property of Knight's/Ascalon armor has been changed? This formerly applied to all hit locations even if only one piece was worn, but rumour has it that this has been 'fixed'.

I don't know where you're getting these rumors from. No, it hasn't been fixed yet. It would be on the Anet Updates page if it had been fixed.

It hasn't changed. Rumors come from this vaguely worded update note:

But people tested it post=July 22, and it was still global damage reduction. Until I see a note in the Game Updates saying "Changed Knight's/Ascalon armor to locational damage reduction", and then test it myself, I won't believe it has been changed.

Whew - guess I can keep my Knight's boots on, then...

The mesmer "+15 while casting" also benefits from this, right? I bought one this for my boots only, although I'm not sure if it's working.

Yes, the Mesmer +15 while casting armor is also universal from what I've heard, haven't gotten around to testing it myself though.