Remember, the Echo is still in beta testing. Its only sold to Amazon Prime members at this point. It is a work-in-progress.
When talking about the Echo, never forget about privacy, as well. i believe the Echo "listens" for its name in hardware, then when it hears it, it sends the voice command and small bit before and after it to its service center for processing. i trust that Amazon is not going to do any evil with this information, but of course the Echo firmware can be remotely updated, so a hacker could conceivably change what the Echo does. Other products like the Wink and Start Things sends your command into "the cloud."
If you haven't seen it already, last weekend a movie called Citizen Four was released on DVD and Apple/Amazon/Google video, etc. Citizen Four was the codename that Edward Snowden first used when communicating with reporters. This movie won the Academy Award for best documentary this year in February.
The movie is chilling, and even if you think you know all the details of the story, I can tell you there were some facts released in this movie that have never been reported elsewhere. And I believe the story is still evolving.