We have automated the hell out of programming (compilers, shared libraries, higher level languages, etc), but as soon as we do that, they just expect us to be more productive :)
I think it will be still be a long time before robots replace humans, even at Wal-Mart-like jobs. There are a few places where it's appropriate (self checkout, for instance), but there are things that humans do without batting an eyes are very very hard or expensive for robots (spoken communications, visual and auditory classification, spatial navigation and obstacle negotiation).
Humans aren't really that expensive honestly. Considering that the rent on a few servers from EC2 can equal the hourly wage of a Wal-Mart employee, it's going to be a while before these equations start working out.
It's not just self-checkout, but things like vending machines (big in Japan, will eventually be big everywhere else; this is starting to occur now with DVD rental vending machines) and robot warehouses (Kiva already does pretty well with this). Also Amazon and Netflix. Their warehouses may not be run by robots, but are extremely automated. This also applies to food - there's no reason automats can't make a comeback. I also don't doubt for a second that one of the first things Google will do with self-driving cars is automate the trucking industry.
You're absolutely right about people not being very expensive though. Labor costs actually make manual manufacturing in China less expensive than in fully roboticized factories in Japan or the USA for many things.
It's pretty fucking hard to automate programming. Heck, we can't even solve voice and character recognition.