This is perhaps the FAQ entry I dislike the most in the entire document.
("Strictly as a matter of convenience"? A longsword changes its designation when someone switches hands? Ick.)
It brought me great joy a few months back when I queried CustServ on this one, and they indicated that they were in the process of trying to get that FAQ entry removed or changed.
That joy is fading as time passes and it still hasn't happened.
But the answer has always read to me as though Skip Williams had somehow missed the changes to the weapon size rules from 3E to 3.5, or disliked them and wanted to ignore them; how the answer "a longsword used in two hands is a two-handed weapon" could exist alongside references in the Core Rules to "a one-handed weapon wielded in two hands" (presumably, by the same logic the FAQ is using, I can wield a greatsword (listed as a two-handed weapon 'strictly as a matter of convenience') in one hand, which would make it a one-handed weapon?) eludes me.
I'd be interested to see Andy Collins' take on the same question - is a human using a Medium longsword in two hands wielding a two-handed weapon? Or a one-handed weapon wielded in two hands? I get the impression that he was more involved with the PHB side of the revision, and the weapon sizes in particular, than Skip was.
-Hyp.