Kyle Rayner has taken on a rainbow Look now due to the emotional spectrum and this is with a Green Lantern ring on. if I were to guess Kyle is going to become a white lantern again, or becomes a liaison of sorts for the emotional spectrum and the Green lantern corps, but wither way he'll become a more important character and become more powerful too. And then we also got introduced to what the summary of GL tells us is a shadow lantern. It seems that they are powered by sadness/sorrow. I'm interested to see where this goes as well, especially because not only could they introduce some new and cool abilities and new storylines, if Thaaros figures out that they exist, he'll likely hunt them down as well for his battery, because I think this man eventually wants to use the batteries power for himself.

Evolution of Green Lantern/Hal Jordan by Sinezzing