You guys realize that the lighting in those new images is completely new as well? It's not like you just load up the same level and it magically gets nicer... All the lightmaps have to be recalculated too.
Though as I hear, LightMass is kinda easy to use and relatively fast, too.
Yeah the improvements are specific to that build of the engine. If you want to see that in UT3, I'm guessing Epic will have to release a hugeass patch and replaces a lot of the existing level and engine data. (that said, they have done a couple 400mb and 500mb "titan" patches)