"Computer!", hailing a machine to await your command, has been embedded in popular Science-Fiction for a long time. In 2015, all major smartphones offer a digital "personal assistant" that is controlled with voice commands, whether it is Google Now on Android, Apple Siri or iOS or Microsoft Cortana on Windows Phone. More recently, similar systems have expanded outside of smartphones, like Amazon Echo or Microsoft Cortana on the upcoming Windows 10 (the first builds with Cortana embedded are available). Most usecases focus on the collection and relay of information, like "what's on my schedule for today", "where is the closest fuel station" or facts you would otherwise type into a search engine. Some functions are more active, like writing e-mails, playing music or entering appointments into a calender. None of these female-voiced interfaces offer really new things for users to do, it's just a new way of accessing the same information and tasks.
There are two things that dampen my excitement about these voice-controlled interfaces.
First, the usefulness. When I imagine how I would use these functions in everyday life, very little comes to mind. They are like the products from infomercials, made to solve problems that don't exist. The voice interaction seems most useful when driving, when you don't have your hands free to type. However, there appears to be little use for voice searches at home or outside. With other people around, talking on your phone is obnoxious enough, but talking with your phone is a whole other level, especially since you hear the responses as well. In an office environment (when it comes to Cortana on the desktop), it is too imprecise for people in their own rooms and too loud for shared office spaces. Also, keep in mind that these products are sold as personal assistants, which is a way for people to compensate for their own lack of organization, but when they are the only human logic involved, the digital assistant will be just as cluttered as the users themselves.
Second, the backend. All these interfaces I mentioned are powered by systems outside of the user's control, like the Bing engine, Amazon's infrastructure or Google's conglomerate. It certainly makes absolute sense to use these immense sources of information to make the assistant software as competent as possible, however you're using them as a service, you don't own this software. There is no server you control yourself, it's all in the datacenter of a foreign corporation, i.e. "the cloud". This means that not only is there a pulling of the information towards you, there's also a pushing of information about yourself into a profile that is kept somewhere out of your control. Microsoft for example promoted that you can delete fields of interest from your Cortana profile to make searches more relevant, but it is to be expected that they are not removed from your profiling, only not used in searches. You effectively have no control over what information the software vendors collect about you.
2015 and 2016 are the make-it-or-break-it years for voice controlled computer usage. While I don't see a really broad adoption soon, it might become a popular gimmick for mobile devices at least for a while, mostly because it makes some things more comfortable, which appears to be the major concern for consumer electronics. On classic desktop PCs, I don't see these assistants becoming more than a gimmick nobody really uses productively. Computer, post this article on the Internet!