Except the containers aren't typed. They are essentially containers of void*. If you believe that to be "generic", then you don't understand the topic.
You are right, I overlooked the magic of Go's build-in containers (I admit, I haven't touched the language after we looked at it around a year ago). I amend my comments to apply to user-defined containers and types, where generic == interface{}...at least, it did when we tried the language out.
This is an example of a simple "generic" in Go, as I recall it:
type mytype struct {
mydata interface{}
}
The casting this requires felt like a step into the past when you're used to eg the STL.