This was shown at the D23 Expo (a convention for Disney fans held last week).
Although it was posted on YouTube by a spoiler site, the video itself appears to be spoiler-free. It’s comprised mostly of clips from Season 5, and touches on the main events and themes of that season. It also has a few quick glimpses, from earlier seasons, of some familiar faces that we haven’t seen in a while.
The narrator says:
All the lives on board Oceanic Flight 815 will find the answer to the biggest question of all.
Can’t wait! Less than five more months to go. Ha. Being a LOST fan is like taking an advanced-level course in learning how to cultivate patience.
Video by ODI TV Spoilers