Personally I'm all for Lee not becoming a casualty and remaining the lead protagonist for the forthcoming Season 2. I really rather like the idea of him being akin to Rick, becoming the leader of a new group in the wake of Lily's departure and finding new folks along the way, building a new group with Lee and Clem obviously still with him given choices we've made.
With Rick in TWD graphic novels we see the world through Rick's choices and those made by the people who travel with him. In TWD game we see that same world through Lee's choices, i.e. choices we make. I don't quite see the point in setting that up with Lee just to kill him and bring in someone else. From a narrative perspective, in a (hopefully) long series like this, it just doesn't make a lot of sense. People get attached to a character who's shoes they've walked in, and filled, for an extended length of time.
Also we have a vested interest in protecting/raising Clementine (some of us anyway) and having Lee die just so Clem becomes a new player character smacks of lazy writing. If I had my choice I would like to see Lee and Clem truly growing/aging in this world, the choices we've made reflected in her and continuing to matter as she becomes older and starts to try to find her own way.
The "years later" time jump gimmick has just become an easy way out in too many well written stories/series of late. It's something Robert Kirkman has tried to avoid in TWD graphic novels for the most part and I'm hoping TellTale does the same.