I'm looking foreard to the game, as I am a Wii owner (Though I also own a PS3). On some level, I'm glad. But those graphics are definitely sub-par. The wii can do so much better. Will they look better on a real Wii? More than likely, but not by much.
Screenshots are compressed jpegs, the full resolution would be better. The game will probably run in Progressive Scan which would make it sharper, and in motion would hide the jaggies better. Not to mention the fact that it will probably run in widescreen (since the Wii can).
Now, will it look much better? Doubt it. But I definitely think it will look better, but still no better than Emperor's Tomb, which I can live with. Hell, I can live with just about any graphics as long as I can make things out, which, hopefully I'm right on the graphics, and things will be clearer on a real TV on a Wii.
Hopefully, gameplay-wise, it will play well. Our best hope for that is if the Wii version was the primary one that was programmed and all of the others are ports, albeit with the graphics being standardisez across the level.
Story-wise, I think we'll be okay. The only gripes most people had with the stories to IM and ET was the extra-dimensional stuff at the end, and since this artifact is Biblical (and is just a staff), I don't think we'll end up in any other dimensions at the end of the game. At least, that's assuming Indy can't use the Staff to open a dimensional rift. But even then, I didn't mind these portions of IM and ET. But I'm a flexible guy.
At this point, I don't see much point in complaining about things until we get to play the game for ourselves.