Yes, your rig falls into the "medium" detail settings. You will be able to play at good framerates with a lot of the eye candy intact.
People need to remember that Doom 3 has so much eye candy, some of it can't even be enabled on current generation hardware. And I'm betting that even on a modest rig, Doom 3's texture detail, character models, and physics engine will blow all games out of the water.
If you want high detail, you'll need a next-gen vid card.