I think this thread somehow has no meaning. All of us are Pokémon fans, and except for the rare few, we will still play the new games regardless of graphics.
However, if you think on a broader scale, outside of loyal fans, then you will realize that there would be very different responses than the ones from people posting here. For example, if when they made the new DS Pokémon games, they used FireRed/LeafGreen graphics, many people would complain. Fans would still play the games, but many others who aren't fans might have less reason to play them. When they make new games they have to consider drawing new fans in, so they try to create graphics that best suit the console they're working with.
In this case, they moved to the DS which has better graphical capabilities, and thus took advantage of those capabilities. I think they feel, however, that they couldn't have went fully 3D, because that would feel somewhat foreign to veteran fans of the series. So, the game has mostly 2D graphics, with the 3D perspective rolling effect on the overworld sprites, and 3D level graphics.
I like the direction they took with the move to the DS. I'm always open to improvements in graphics, and in my opinion, they improved them. I never liked their 3D rolling effect, because it makes the sprites look pixelated, and they should be anti-aliased on top of having that effect to remove the pixelation.
I'm actually glad they kept those graphics for HeartGold/SoulSilver, because I've taken a liking to them.
I just wish they had kept Kris from Crystal instead of completely replacing her with someone else. (I think they don't like blue hair. :P)
