Boy, was that excitement wasted!
The content is exactly the same as the original; six episodes of pointin'-and-clickin' fun. (The Wii added some bonus content like sketches, but who cares about things like that?) The PC version had a flew flaws (repeated scenery, slow pace), but the writing and voice acting was so strong that it was easy to look past them.
On the Wii, though, the flaws are amplified as this version brings a whole new set of problems. The unreliable Wii remote makes utilizing inventory, options, and dialogue choices cumbersome -- actions that could be accomplished quickly in the PC take more than 20 seconds to accomplish on the Wii. Even though the graphics have been downgraded, the Wii can't quite catch up; during the chase in Episode 1, the graphics lagged so hard I was having flashbacks to Shadow of the Colossus, and I only passed that section due to luck more than anything else.
Sam & Max is a wonderful and hilarious game. But get it on the PC and avoid the Wii port.