My guess is the latter. Walt erased himself and went into hiding. He's not just going to suddenly change his mind and say "ok, now I'm ready to go back and get those guys." I think more likely, the crew starts rough ridin' with Walt's family (his house was trashed, Heisenberg on the wall, etc.) to lure Walt out of hiding.
And I'd guess that Jesse is behind it all. He's not done with Walt yet.
Walt’s final words to Skylar on the phone... “I’ve still got things left to do.”
Walt formulated a plan somewhere between the point he fled his house and the point where he called Skylar and left Holly at the Fire Station.
Regarding Jesse, I agree that everything that happened in the desert indicates that Walt is about as "you're dead to me" as you can get. But, I still think he either did that for some unknown reason (this show is BITB when it comes to twists and turns) or he simply had a change of heart.
Walt is a complex character who, even in at his darkest, continues to be humanized (Skylar phone call, begging for Hank's life, etc.) If Walt had just given into the darkside, this show isn't compelling anymore. The reason it's compelling is because Walt is a monster who you feel is still capable of becoming human again (scene with Holly).
He tried saving Hank (family member who mumped him), he's tried saving Skylar (family member who's mumped him and Beneke), and he considers Jesse family. So, yeah, even though Jesse has mumped him, I can see him try to save him too.