Hyper threading was originally developed to make a CPU more efficient. For example one thread would be doing a floating point operation while another would be doing integer operations. If both threads needed to use the same resources, such as the same integer register, then one would have to stop and wait it's turn. It's like your left hand can use a screw driver, and your right hand can use the wrench, but you only have one of each so if the left needs the wrench also it needs to wait it's turn.
It seems like rather than copying Hyper Threading, AMD wants it's core to be able to execute another thread regardless of what the first thread is doing, basically giving it two wrenches and two screwdrivers rather than one of each. We'll see if it manages to work that way or if it really just ends up being hyper threading.