A new Pokemon Heartgold and Soulsilver video was released recently. From this video, we can tell that the 3D capabilities are used more throughout the game, the same as in D/P/P. These 3D capabilities are used in the buildings, and in the start-up screen where we can see Ho-oh or Lugia flying. We can also see in the video some locations from the games e.g. Tin tower, Slowpoke well. We can also see the new look berry bush.
But one of the main things about this commercial is that near the middle, it shows us some more about the Pokewalker, and how it is to be used. It also shows us some box art.


Heartgold box art



Soulsilver box art


Info found at: http://www.pokemon.co.jp/special/hgss/special/movie.html