Q u o t e: Should D3 have better graphics? YES.
Is it going to? NO.
Sigh.
The graphics, just like in SC2, GW2, and EVERY OTHER recent and upcoming game, will have adjustable graphics. You can adjust AA, AF, and vertical sync, and there's a slider for graphics quality like every other video game has, among other things.
Your computer sucks? Set the setting near their lowest settings.