There's an update being pushed out today that gives us the unified IDs, Miiverse, and making it harder to accidentally opening the camera.
Also NNIDs are still tied to WiiUs (i.e. get a new WiiU, have to use another NNID). Not sure if this is similar on 3DS side (going to pick one up today).
Unless I am completely mistaken, same for the 3DS side of the house as well.
Like I said above, Nintendo is "starting" to get it right...nowhere near finished, however
NNID will now be also locked to a single 3DS at one time, so if you happen to lose your 3DS, you will lose the ability to use that same NNID on any other 3DS because Nintendo has said they don't have the ability to remotely remove it from that one 3DS that was stolen/lost/whatever. So, great going Nintendo Even if they somehow did make it available for you to log into another new 3DS with the same NNID, you will still lose all your purchases at least.