If there was a new GF game, I'd like it to be a sequel with a new character. I love Manny, but his story has been told. However, I don't think it would be too bad getting a game in which the character's adventure takes place at the same time as Manny's.
We could have an LSA agent who travels around the Land of the Dead on a secret mission from Salvador and gets caught up in other mysteries as he goes. He could easily meet Manny at one point or exchange letters with him or something.