They had no concrete plans for the specific cliffhanger at the end, but for the show as a whole we got some closure in Garcia’s AMA at least. If you haven’t seen it:

I had always had an ending to Earl and I’m sorry I didn’t get the chance to see it happen. You’ve got a show about a guy with a list so not seeing him finish it is a bummer. But the truth is, he wasn’t ever going to finish the list. The basic idea of the ending was that while he was stuck on a really hard list item he was going to start to get frustrated that he was never going to finish it. Then he runs into someone who had a list of their own and Earl was on it. They needed to make up for something bad they had done to Earl. He asks them where they got the idea of making a list and they tell him that someone came to them with a list and that person got the idea from someone else. Earl eventually realizes that his list started a chain reaction of people with list and that he’s finally put more good into the world than bad. So at that point he was going to tear up his list and go live his life. Walk into the sunset a free man. With good karma.