While writing Illuminated Pixels, I interviewed friends/associates who worked on many different kinds of projects to find out what techniques the studios are currently employing, and with what frequency. It was interesting to me to find that today's digital lighters have more options in technique than ever before.
I had originally thought that many of the old tricks weren't really used much anymore, if even at all. For example, at Sony Imageworks, where I previously worked, they have completely left behind many methods which used to be standard, and entirely embraced newer methods. More specifically, they are now render with a dedicated ray-tracer which does ray-traced global illumination, and do not use things like scanline rendering, depth-mapped shadows, or cheated reflections at all. With a dedicated ray-tracer, that would be silly - they use ray-traced shadows and ray-traced reflections. I wondered if this was common for most of the studios.
As a general trend, the move has been towards greater realism in lighting and shading. However, I was surprised to find that some cheats which I thought perhaps were obsolete were alive and well, such as using reflection cameras to cheat a planar reflection (refer to the book if this technique isn't familiar). It really just depended on the studio. It depends on the level of realism they want, the amount of creative control they want, the amount of time they are able to dedicate towards rendering, and the abilities of the artists they hire, etc.
So today, depending on the project and the studio, digital lighters may employ both newer techniques and older techniques. To me, this is both fun and exciting. It also is why it is good to know a variety of techniques, and furthermore to know the pros and cons of them, so you can best decide which one to use on a particular project (if you are doing the deciding) or at the least be experienced and competent in a variety of approaches, which will employers will appreciate.