Google will apparently be calling it Majel. Voice controls for Android have been there for over a year now, allowing you to write text messages, emails and so on. The only thing Apple's Siri really has the edge on, is the way of speaking naturally, as if you're speaking to a person.
Knowing Google though, they may come out with something that out performs Siri on every level. Especially because Google will most probably release API's right away, allowing developers to integrate it with their apps - this is where Siri falls short.
It's great to hear Google might be working on something like this but there is no confirmation date for when it will be released. It may be at the end of this year, even though we're half way through December or, January/February release. This is a rumour so take everything with a pinch of salt. Details are very sketchy and there is no evidence there will even be such a thing.
If you think you can find out some more details, from reliable sources, let us know!