It's been reported a few months ago that Google may be working on an alternative to Apple's Siri, and it seems they may be ready to launch it by the end of the year. I wonder if this means it will be an update to the OS, or just an app. I think if they want it to work very well with the OS, it will have to be an update, rather than just an app. We've already seen some apps that work like Siri for Android, but they haven't been that good (not that Siri is particularly more useful), but it was mainly because they were built pretty fast and didn't have such a good AI.
I still think Siri is mostly a gimmick, and it took off in the beginning because people liked to show their friends what "silly things Siri says", but beyond that it's hardly useful for more than a niche of users who are perhaps business users and want to be constantly reminded of their calendar schedules. Even one of Siri's more "useful" features, that of asking it questions about something and it answering you, is still not something people are going to use on a daily basis, maybe not even on a weekly basis.
Google has had that for years with Voice Actions, and the only difference was that it just showed you the results, rather than speak them to you as well. Some may also think that it's weird to talk to your phone like that, especially in crowded places, and I think even if people wanted to really use it like that, it would still take a while before they got used to talking to their phones, even at home.
It's possible that Google's alternative (code named Majel) could be much better than Siri, but I'm not convinced yet, it's going to be very useful, until that kind of AI is so smart that you'd think is a person, and not bound by just showing you results from the web. Until we get to that point, I doubt many people are willing to talk to their phones.
Matias has talked before in an interview about their possible approach to this:
"Our approach is more like Star Trek, right, starship Enterprise; every piece of computing surface, everything is voice-aware. It's not that there's a personality, it doesn't have a name, it's just Computer."
So perhaps Google's approach will be that you'll be able to interact with the phone or other Android based devices at all time, without having to press any button, or name it. This might work better for Google TV as a way to interact with the interface, rather than their initial approach with a keyboard. Either way, we're probably going to see this sooner than expected.