Matt said during the demonstration that all their stuff right now uses the "simple shadowing" (I think he called it) that's the normal dynamic stuff - when they get the lightmapping stuff in, I imagine that's a bit part of what it'll be used for, though I'm curious where they'll store the lightmap data. If it's separate, they might actually take a memory hit by doing that (one nice thing about D3 is you take precisely 0kb texture data on lightmaps, though pay for the shadow calculations and such on the CPU at run-time), but they might be able to (and may well want to) bake it into the texture page for the world itself to keep it in a single pass. That's just level designer speculation, though ![]()
I imagine they'll also support something similar to unreal where you can get both baked and dynamic light/shadows out of single light sources on a per-object basis.