We got it on Sunday, for $250 you get all you need to build your robot (vehicle, animal or humanoid) and program it as well. Nicole (6) and I started with the basic vehicle robot and we had fun building it (similar to puzzle activities, very calmed and focused activity which is great for Coco) and then we programmed it to go and come back at different speeds and simple things like that. The following days we added one build feature a day and programmed it. The latest one is able to go, sense a ball, grab it and come back (it doesn't always work, but pretty cool).
This weekend we'll get into the human bot and we'll experiment with more sensors. Nicole does not completely grasp the programming part, which basically is choosing a tool for a particular function (go, wait for sensor, sending forward or back movements to servos, etc) and then setting some properties (for instance which port to use, it has 3 output and 4 input ports). She gets the tool part but still didn't get much involved with the properties, as for now it was all new, we'll focus in some things at a time.
It really seems to be a great learning tool. For one thing she can program a machine and see the results out there in the real world, which is for sure easier to grasp and similar to what the future world will be more and more about. On the other hand it does require a certain degree of conceptualization, logic thinking to program something you need to define the steps to go from A to B to C, etc.
I think it'd be nice to have some tool simpler even than their dev language to teach my little one Angelina, when she's about 4 probably.
We plan to add other devices like a wireless camera to send images to the computer and extra stuff like that when we're done playing with the lego set. The Microsoft Robotics Studio is supposed to be able to program this lego bot as well.