There are several games that come to mind.

Indiana Jones and the Staff of Kings was due to be released on mutiple consoles but the leaders were the Xbox360/PS3 versions.

One of the selling points was a unique ragdoll system which meant when you punched a bad guy, there was no set animation of them falling down. The ragdoll physics did it's job.

There were several videos released during production, usually at E3 shows.

Sadly, the delays keeper getting longer. While there was no official release date, we wondered if they would tie it on to the release of Crystal Skull. The film came and went both theatrically and on home formats but no game.

Then one day, the first official trailer was released, I watched it with excitement. Then the gut punch, at the end of the trailer, it only had logos for PSP, Wii and DS.

Soon after, we learnt the game was cancelled. Some early rough gameplay footage is online.

Another is Star Wars: 1313. The game would tell the story of how Boba Fett became the famous bounty hunter and acquire the armour. This E3 trailer got me so excited.

I think the game was cancelled when Disney bought Lucasfilm.

Finally Star Wars: Rogue Leaders.

Essentially, the two Rogue Leader games from the GameCube remastered for the Wii.

According to an interview, this would have been pushing the Wii to it's graphical limits, I think they mentioned 60fps.

There was also extra Wii enhancements such as lightsabre battles with Wii MotionPlus remotes and even using the Balance Board as part of ship controls.

If I remember rightly, the game was fully finished but they couldn't find an interested publisher. He's the trailer.