One of the most unfortunate things about Grim Fandango is that it can be a bit tricky to install or get running properly on Windows XP. Recoding the game for the Wii's hardware would be the first step in porting it and would eliminate any hardware issues -- no fiddling with Windows 98 compatibility mode!
Oftentimes the Wii's 480p output seems lackluster in comparison to the competition, but in Grim's case, it may be a blessing in disguise. Re-rendering the game's numerous backgrounds and cutscenes would be a lot of work Lucasarts likely would never go for, but the Wii's max resolution would be able to handle Grim Fandango's existing assets just fine. While the 3D models look dated and blocky, the prerendered stuff still looks great. New character models would ultimately make the end product look a little better, but the blockiness does little to harm the presentation. The controls, on the other hand, could use some work.
Unlike the point-and-click adventures that preceded it, Grim Fandango opts to do away with the mouse completely and rely on the keyboard or, optionally, a joystick (who still has a joystick these days, anyway?) Manny is moved via the directional arrows, and the Enter button interacts with other characters or objects in the environment. The I button opens the inventory, the P button puts items away, and the number keys 1-9 can instantly switch to items. Finally, the E button examines things that can be interacted with and the Shift button makes Manny speed up to a trot.
The biggest problem lies in the arrow keys. Moving Manny around the environment is often awkward and sometimes frustrating, as he has trouble turning when brushed up against a wall, table, or any other solid object. It can also be pretty tough to position him properly to examine objects or talk to NPCs -- on the bright side, Manny moves his head as visual clue when he's near something that can be interacted with, eliminating the prospect of frustrating trial-and-error movement.
I suspect making Manny's interactions with his environment a smoother experience would take more than a new control scheme, but fixing the bugginess of the movement and having a superior control stick in the nunchuk would be a one-two punch to Grim Fandango's biggest problem. Using the nunchuk for movement and the Wii Remote for interaction and inventory management would closely emulate the layout of the original game.
To change things up a bit, Grim Fandango could alternately be adapted into a classic point-and-click setup, using the Wii Remote alone to move Manny, interact with objects and control the inventory. This could be accomplished pretty easily -- simply add an on-screen reticule that can be used to lead Manny around in the vein of The Legend of Zelda: Phantom Hourglass.
Even if Grim Fandango was rereleased on the Wii without any substantial improvements, it would still be worth a purchase. The adventure genre is sadly and sorely underrepresented -- thankfully, the folks at Telltale seem committed to continuing to support it. Though not a point-and-click adventure game, hopefully Tim Schafer's upcoming Brutal Legends will sell well enough to rekindle a corporate interest in his older projects and Grim Fandango will rise again to show us all how much better life gets after death.
In the meantime, if you can't get Grim Fandango on the Wii, how about getting the Wiimote on Grim Fandango? A certain resident GlovePIE wizard can give you the skills, and The Department of Death can give you the tools. Hey, it's almost as good as the real thing!