I never thought to highly of McGreevey, but he should not have to resign just because he is gay. A few things were unclear after the press conference. If he was just having an affair, that's not really big enough of a deal to kick someone out of office. No mention of the civil lawsuit. There must be something damming there.
That being said, I don't believe I just watched my state Governor come out of the closet of national TV. That does not happen often. That must be the most public high profile closet bust out in history.