I have no idea how things connect, and some is probably an amalgam of other predictions, but heres mine (rambling):
Walt: Eventually takes the ricin, and dies in the desert, marking the graves of Hank and Gomie
Jesse: Gets the M-60 from Walt, goes apeshit on the nazis, before he finally gets clean and takes care of Brock (somehow)
Skylar: Killed or at least attacked and left crippled by Marie who found out about the money-laundering (and is by proxy partly responsible for Hank's death)
Walt Jr: Ending scene is him eating breakfast with his babysister, in Hank's old house
Marie: Killed by Jr. after she attacked Skyler
Todd: Killed by Jesse(?) at the compund, somehow compromises the methcooking because of his feelings for Lydia
Lydia: Killed by Jack (see "Todd")
Jack: Killed by Todd, after killing Lydia
Gretchen/Elliot: Gets an intense Heisenberg- verbal shakedown, donates money to Jr./Holly.
I realize this is alot to fit in one episode, and I dunno how they'll manage, but we'll see, it's gonna be one epic finale, that's for sure.