For an example of this goto Food 4 Less. No stockers (they just cut open a case and stick it ont the shelf) and no baggers (you bag your own). Most rich people don't like bagging their own groceries so Food 4 Less tend to be in low income areas. They want people to wait on them hand and foot with a smile, but don't want to pay. Personally I have no compunction about shopping at Food 4 Less, but most of you would cry about the lack of baggers.
As for completely automated systems they have systems like that installed at the Ralphs here in San Dimas, CA, and I have also used them at K-Mart. They are the biggest piece of crap every invented. You scan your own groceries and place them in the bag. If you can't place the paticular item in the bag because say for instance it doesn't fit the machine will whine and implore you to "Place the item in the bag" and won't let you scan the next item until you comply. If you decide you don't want something and try to delete it the entire machine has to be reset by a person. These things are a joke, and it's not like the grocer's pass the savings along to you for doing the scanning and bagging yourself.
In the meantime while the Grocery store workers union are just trying to hold the line (an endeavor I doubt they will be successful in) LA County Sheriff's are threatening to walk off the job unless they get a 3% salary INCREASE! Amazing...