I got two of these for Christmas and also a wifi plug-in receptacle which we used for our Christmas tree, but now is connected to a bedroom lamp. This means that I am always only a shout away from illumination. A light switch does one thing, but these do it so much better that I can't imagine going backwards from here.
The Dot has drastically changed the way I think about future purchases. With every new appliance I will seriously consider if Alexa integration is a part of it. I have already added the Logitech remote hub to my wish list. I am wondering at what point it would make sense to put a wifi lock on my front door. And I'm very hopeful for a price drop in wifi thermostats (there is not much reason for these to cost much more than than the light switch as the server software could handle the "smart" features).
Another great thing about the Dot is that it should move forward in abilities without needing new hardware. It is really only a wifi microphone, and it is remarkably good at that already. It can hear me from the bedroom or at the bottom of my basement stairs. Since it's job is to hear what I say send that to the Amazon servers then relay message back, it is up to the servers to get better. Which they can and will. Maybe it's only a matter of time before I can say, "Alexa, what was that thing I was thinking about the other day?" Until then I'll still have to rely on my wife for that one.