Has never driven in snow OR heavy rain
Cannot avoid pot holes
Would ignore a police officer waving for it to stop
Would fail to recognize a new stop light
Cannot drive in a large, open parking lot or a multi-level parking garage
Cannot read a traffic light if the sun is directly behind it
Objects on the road are avoided regardless of what they are (so a plastic bag would be treated like a rock)
Google's self driving car is not really driving on the road. It is driving on a map.
"intricate preparations have been made beforehand, with the car’s exact route, including driveways, extensively mapped. Data from multiple passes by a special sensor vehicle must later be pored over, meter by meter, by both computers and humans. It’s vastly more effort than what’s needed for Google Maps."
Yeah, that whole google taxi thing is probably more than a few years off.