I just highly doubt they will even have an "Ending" to the zombies storyline. I mean, then what happens when 3Arc releases the next installment? No zombies? New storyline?
what i have heard is that isn't going to be another map pack for black ops. Have you lot been watching the Call of the Dead major easter egg? The old characters Dempsey/ Nikolai/ Takeo/ and Richtofen has been locked in a room and there asking the new characters to help release them, Freedom could mean when you complete the Major Easter egg you release them from the room.