Read somewhere that the writers wanted to turn an ordinary guy into Tony Montana.
Walt & Junior actually watched 'Scarface' in a recent episode. Maybe these points are red-herrings to get us to think that that's how it's going to end, because this show is seldom straight-forward.
Plus when you think that there is only 1 year between episodes S01E01 & S05E01. We have the bones of another year in Walt's life to get to the opening scene (bacon on eggs in the Diner, before he gets the massive gun) in episode S05E01. It is difficult to see how we are going to get there in the remaining 11 episodes.
Still it should be an interesting ride.
As for the most recent episode, I was just waiting for the kid on the bike to turn up, so it kind of took from my enjoyment.
Still the best thing on TV by a mile though.