It's nice to be optimistic, but you have to consider the following:
- The designer and writer of Grim Fandango, Tim Schafer, no longer works for LucasArts. He now heads his own development studio, Double Fine (
http://www.doublefine.com/), which already has one game out. Make sure you play it!
- Most of the Grim Fandango team no longer work for LucasArts, and many went to work for Tim Schafer at Double Fine (
http://www.doublefine.com/).
- The storyline of Grim Fandango was closed off perfectly; it cannot realistically continue without destroying the notion of Manny Calavera finally reaching the end of the long, hard road to peace.
I'd love to see the world revisited just as much as anybody, but the above points reduce the chances of a second Grim Fandango from LucasArts being any good to an almost non-existent degree. I don't think anybody other than the man who crafted the world himself could continue the storyline feasibly and successfully without pissing all over the original like certain other games (
http://www.mixnmojo.com/php/site/gamedb.php?gameid=11) have.