With the Wii being my main console I learned to not care so much about graphics and worry about the gameplay and controls.
That said, if I see a Wii game (especially a third party game) that looks and plays great I applaud the effort.
The problem with third parties on the Wii is that they downgrade their HD efforts very badly, making the game look really bad, and there's the chance the gameplay doesn't hold up as well as it should.
So once more, the reason we are going ga-ga over Overlord's visuals and gameplay is because this looks to be a well polished Wii game and the fact that its happening makes us very happy.