I also did some media tests in UDK recently, namely re-visiting god-rays (about time!) and trying out sky-domes. These were both surprisingly easy in UDK, god rays especially when compared to all the trouble I had trying to achieve the same effect in maya.
I took the time to get acquainted with the options for the light, and had a bit of a play around with changing the colour, increasing the intensity of the god rays, and the brightness of the illumination etc.
Obviously the above looks a little weird considering the sky texture used, but i certainly plan on having a warm glowing light like this in the garden at the beginning of my project.