(thanks to a wiki contributer) ok i'll point out a few things from this trailer that are from episode 13 and please add anything else you may know

6.00 - Dayrl and Carol on the motrobike escaping from walkers

14.00 - Andrea running (walkers is my guess) & walkers invading the farm

18.00 Rick reaching out to Lori who backes away (ok so i believe he just tolled her he killed Shane and she's feeling a whole range of emotions, hate, anger, sadness ect)

20.00 - walkers approaching heading towards the farm (but i believe they are the ones after Andrea)

21.00 - Carol screaming (from walker attack) & Maggie trapped (if you listen i believe she's yelling "let me out")

I also believe a few of them barricade themselfs into the farm like Carol and Maggie

Also basing on the new pictures

Carol is saved by Dayrl and they escape the farm by motorbike

A group is Rick - Lori - Carl - Hershal and Theodore

So to me there the only ones cofirmed to get of the farm

We don't know the fates of Andrea - Glenn - Maggie - Beth - Jimmy - Patricia

What are your new thoughts or anything i might have missed

Thank You :)