I know there are a lot of Lisa haters out there, so not sure how many people want her and Dean to get back together. But there is one person who wants to see them as a couple again: little Ben. And he'll do whatever it takes to make that happen. Here's the spoiler, courtesy of Michael Ausiello:
Question: Your mission, should you choose to accept it, is to find a good Supernatural spoiler on Dean. —Kristen
Ausiello: I accept! I accept! Little Ben will attempt to get Dean and Lisa back together using the oldest trick in the book: The bogus emergency!