Generally I would say that if the marriage takes place, you don't owe the return of your gifts, even if it's a very short marriage. In this case, though, I think every indication is that the whole thing was a sham for her TV show and publicity in general. In that case, the gifts were acquired through fraud and should be returned, period.
And don't even get me started on the charitable contribution in lieu of gifts being returned. People are starting to think they can substitute a donation for anything!