I suppose it is a testament to how awesome this show is that days later, I'm still turning over the pizza scene in my mind.
It's just so readily apparent that Walter believes that if Skyler would just give him the opportunity to explain himself, they could put this behind him. Hence the child like enthusiasm at his wholly naive and inadequate offer of a pizza in the way of reconciliation, and the temper tantrum of impotent "WHY WON'T SHE LISTEN?" rage when she shuts him down.
This episode seemed to foreshadow two possible routes for their relationship. The ongoing drama between Skyler and Skyler's boss about cooking the books seems to be laying the foundation for Skyler finding a way to understand Walt did the wrong thing for the right reason and forgive him (Which I'm sure would be immediately complicated by something along the lines that if Walt stops cooking meth for Gustavo, Gustavo won't be able to protect him from The Cousins.), or perhaps Walt does finally have the opportunity to explain himself to her and she still doesn't forgive him, leading to a meltdown and confrontation like the one between Walter and the cop in the beginning of the episode when his explanation didn't get him what he wanted like he thought it would.
Though given how erratic his behavior is getting, I'm leaning towards the latter. I still don't even understand what he was doing in the house at the end of the episode. Did he break in to take a shower (He doesn't have a shower at his place?), or did he take a shower because he had to break in by going through the crawl space under the house? Man's going loco, but everything he does is justifiable to him in his eyes, and everyone else's failure to understand how justifiable it is just pushes him further into loony land.