3. Mags & Finnick
If you've read the book, the names "Mags" and "Finnick" probably mean a lot to you. If you haven't, then... well, those words might as well say "tree" and "sandwich" - that's how good they are to you right now. We'll leave the identity of those characters secret for now as to not spoil anything, but let's just say they'll be joining Katniss in the new arena come tournament time, and - although the marketing department seem to be doing their best to avoid showing fans these characters in any way, shape or form before release day - you can very, very briefly spot them running through the forest in one shot of the new trailer. There's going to be a lot of running in this movie, you see, which isn't surprising, given that we've glimpsed...