ast episode, he kept Skyler alive, despite Lydia's wishes; he grins when Jesse reveals Todd's murdering the kid.
The only way I can rationalize these two actions is that Todd has a strong (albeit fucked up) ethical system. Skyler is an innocent, and thus is off limits; Jesse rats in the video, which suddenly makes the permanent slavery Todd had planned for him justifiable (and thus Todd smiles because he wasn't engaged an an immoral act in enslaving him).
If the show set this up in the second to last episode, it has to pay off in the only episode left: somehow you're going to get a room with Todd, Walter, and Jesse in it, with the former two arguing to the latter about how their actions were justified. I don't think Jesse will find either of their arguments persuasive.
Or in tabular form:
Walt: Assaults Nazi base, is killed by Jesse there.
Jesse: Kills Todd and Walt, lives in anonymity in Alaska.
Skylar: Lives, gets money from Jesse on his way out of town.
Walt Jr: Lives, gets breakfast. (Sorry, I gotta steal this line.)
Marie: Lives
Todd: Killed by Jesse
Lydia: Ricined by Jesse on his way out of town.
Jack: Killed in Assault on Nazi compound.
Gretchen & Elliot: Their office or car gets shot up by the machine gun, but live when Walt finds out someone is still producing Blue Meth under Heisenberg name, cue Nazi assault.