There are so many discussions and arguments between people on the board about who people think Clem is talking about in the preview. I have to admit that I haven't read through the entirety of the board on the subject but I've read a lot and haven't seen this mentioned yet.
Maybe the person that Clem is talking about is both Kenny and Lilly. Maybe depending on who Lee sided with the most in season one will be the person that shows up in season 2. Then again, maybe whoever shows up will be who he sided with the least, causing conflict between that person and Clem.
I think this would be a cool idea and I think it's definitely doable considering it was done with Doug/Carly in season 1.