If they really do use the same Infinity Engine, then yes, it will look outdated. OTOH, I remember playing Ultima V (tile graphics!) and the graphics didn't bother me. A good story line is more important than fancy graphics.
What I was wondering is - how on earth are they throwing new challenges at the PCs? With HoW, you can reach 8,000,000 Exp, so if the same characters were allowed, they'd be more powerful than the Bhaal spawn in BG2:ToB...
@Aegis: Bioware didn't do IWD, they just provided the Infinity Engine. Black Isle designed and programmed the game.