Particularly saying this for newer people. I want this group to remain major spoiler free and people to please respect that. Please. No demo story leak information or if you spot something majorly huge in the background of a video. Minor spoilers I am permitting though.
Minor spoilers consist of what Thane will be wearing and what planet he might be found, teaser images or extremely vague lines. Mundane, silly little things. Some people do consider this stuff spoilers and would probably go dark over that stuff, but in my opinion they are very minor and just encourage the desire to want to play more.
Major spoilers consist of the entire plot or what happens to Thane in the end. Like he never gets a cure and dies trying to save a school bus of children while in the vacuum of space and takes out three Reapers in the process the explosion is that epic.
Myself and many others would like to play the game to find out how the story plays out and ends, good or bad, we want to wait.