Avery and Scott
We'll see these two from time to time. Avery will have moved in with Scott, but Teresa will still be living there. Since Teresa is deaf and in a wheel chair, she will be under the assumption that Avery is the live-in cleaning lady, and Avery will spend most of her time in a maids outfit.
Kenneth and Hazel
Now that they are roommates things are a bit complicated, but Hazel and Jack will be a couple at the start of next season, with Kenneth blissfully unaware that Hazel is scheming him. Also, Hazel will never buy the milk and Kenneth will always be left without toilet paper, but he won't care he'll "just use leaves as usual."
After the divorce Jack will go running to Avery's mom, Diana. Diana will be on board with the relationship, but things will get confusing for little baby Liddy when she doesn't know whether to call Diana Grandma or (step)mom. Diana and Jack will still separate quickly while kissing upon someone entering the room out of habit.
Liz and Criss
Baby, baby, baby! They will have a baby, maybe not right away, but we all want it to happen for Liz. A pregnant and crazier Lemon wouldn't be such a bad story line. Plus, after seeing the plant montage, it's kind of hard to imagine Liz as anything but a mother. I mean, did you see her teaching that plant how to ride a bike?
The Liz as plant-mom montage: