Valve spokesman Doug Lombardi has since issued a statement clarifying that "this quote was 'lost in translation' - Portal 2 does not include support for Sony's motion controller."
The source of Chet's original comments were translated from an interview with the German PlayStation Blog, in which Chet stated, "und volle Playstation-Move-Unterstützung". We can't speak German, but we're told on concrete authority that this statement translates as, "and full PlayStation Move support". We're not sure where the translation error lies.
Two solutions: either Valve aren't ready to announce Move support yet, or the publisher toyed with the technology and decided not to implement it. Either way, Chet clearly thought it was part of the package unless the PlayStation Blog totally added comments to his interview. Which would be pretty dumb.
Of course, given the overwhelmingly positive reaction to the "announcement", we have to wonder if Valve will reconsider their stance on Move support and throw it in anyway. We'll see.