Yeah...
After seeing what others posted, I've changed my mind... I now think Alphinaud is the strongest contender for the chopping block.
If they are gonna kill someone off, it would be the most unexpected... and considering how he is the strongest sidekick character to the WoL (the Robin to our Batman), I think his death would actually have the most emotional impact on players.
I think this is also why we had the odd moment at the end of 4.3 MSQ where we actually played as Alphinaud. This was definitely a weird choice in the grander scope of the narrative... We've seen what other ppl were doing in the story in different parts of the world from a god's eye perspective plenty of times before, but this was the first time the narrative forced us to play as another character, to take on another role other than the one we chose/created for ourselves. Now I'm thinking the developer's did this to subliminally invoke a stronger sense of attachment to Alphinaud from the players. Since we got to play as him, we were him... however briefly, and thus we get more feels when he dies...