ELLEN, PORTIA TO MARRY SATURDAY

DAYTIME sweetheart Ellen DeGeneres is going to wed her gorgeous girlfriend, Portia de Rossi , tomorrow in Los Angeles. An insider told Page Six, "Their wedding is definitely happening," and Saturday is the big night. "Twenty people were invited," said the source, who noted, "Portia is wearing a flowing, form-fitting dress by Zac Posen." We’re guessing DeGeneres will opt for a pantsuit.