Monster Hunter Tri seems to be the biggest third party game ever on the Wii. It's getting a massive marketing campaign, demos already at GameStop, and plenty of push. While I didn't spend too much time with the demo, I can't really say how the game holds up to previous installments. The minor fact that I've never played previous installments might have something more to do with that. Check out this video from the Nintendo Channel. It comes straight from the developer's mouth.