Take all the following with a grain of salt, but here's my feedback from my short moonlighting career as a lighting artist: Its becoming more common with this generation of game development. It'll probably be even more so in the next generation. It's often not just a 'place and tweak lights' job though, as often you'll be…
This is an example of what I think is a kickass lighting artist portfolio: http://portfolio.tomaslidstrom.com/ (but im biased since i work with him and he is awesome) But yeah, lighting and FX often work pretty closely aswell, knowing a bit about shaders and postprocessing aswell as rendering pipeline etc is a good plus,…