When it comes to events at DC, you can always count on Green Lanterns to hold their own epic ones. DC announced "War of the Green Lanterns" beginning in March 2011's War of the Green Lanterns #1. The story will continue in the Green Lanterns titles in March, April and May.
There isn't much information available at this time except that we will be seeing something that will tear Hal Jordan, Guy Gardner, John Stewart and Kyle Rayner apart from each other. Each Lantern will be tested and tested against one another.
After the Sinestro Corps War and Blackest Night, what could cause the Corps to turn on each other? We have a few months to think about it. Keep an eye out to see if any clues pop up before then.