So what do you find so impressive about the lighting in those tiny gifs, the muzzle flashes or the muzzle flashes?
And while I'm partially joking, besides that awesome lightning strike and explosion on the troop transport, the rest is all flashlight and muzzle flash. Dynamic physics, post processing effects, animation? Godly. Probably some of the best seen. But the lighting is not leaps and bounds above Halo 3 and we're talking about a game that isn't released yet. Not in those gifs anyway. Hell, look at that massive lightning strike at ground level. The entire area should go from darkened to lit up like the world's largest flash bulb was just snapped. What happens? Almost no change.
Let's do it like this. Halo 3's lighting is spectacular. Very awesome. Most people who have played it agree. Whether you are in "photomode" applying sweet post processing effects to your filtered shots, or just trouncing around live in the multiplayer, the lighting reacts very realistically. Materials light as they should, bloom is applied naturally, saturation effects add to the realism. Nice stuff.
And yeah, those KZ2 gifs are pretty neato too.