Can everyone stop the Google hate for a minute and see that Echo is getting a competitor, and remember that competition is good? Echo can be characterized as an Amazon.com purchasing assistant as much as Google can be accused of using their device to mine data, and if Apple were to ever make one they'd be accused of grossly overpricing their hardware since that's where they make their money.
I realize I'm on MacRumors but come on, don't you remember that Apple gave data to the NSA too?
Back to the project at hand, those who own an Echo absolutely love it, and it seems Amazon can't keep it in stock. You can't knock the device until you've actually given it a try. True it's not for everyone, but many people are finding it helpful to have around.
Microsoft had similar plans with their Xbox add on Kinect about having an always listening component. As someone mentioned earlier, we're moving to a place where there will be digital assistants like Jarvis (from Iron Man) that are waiting for your command. Google arguably has great access to information and more than decent voice search tech so it stands to reason that they would enter this domain.
Anyway, perhaps you think I'm naive but I highly doubt Google's listening to EVERYTHING, rather when you use the key search phrase, like say "OK Google" (similar to "Alexa"), it will record what you search for and use that to build its database for you. For example, if you search for "vacations to LA" then maybe the next time you're on your computer that's the advertising you'll see if you're logged into Google. And that does not bother me in the slightest because that's what happens right now when I search on Google, the difference is simply instead of typing that term into a computer I spoke it to Google. (Actually I can speak it to Google.com too, since it does have voice input on the search page).
Those searching with Duck Duck Go are of course not going to buy this.
Of course when Apple makes their almost-perfect version 1 that promises to never sell the data and uses Siri with some other search engine, you'll have your 3rd option. But it seems Apple won't jump in unless it sees a market, and by Google creating a competitor, that's actually what's happening.