Arriving on Tuesday, multiple tests showed that the new search app was both markedly quicker than Siri, and highly accurate as well. The Google Search App even shows users voice transcriptions as queries are spoken, whereasSiri does not do that until users are done speaking.
Of course, since Apple does not allow default applications to be changed, Siri on iOS may be easier to use than Google Search, but Google definitely has a viable rival to Siri available. In addition, since the technology exists in Jelly Bean, as well, it serves as a demo for what Android 4.2 users can expect, and ... what owners using Android 4.1 that are expecting Jelly Bean soon (such as owners of the Samsung Galaxy S III) can look forward to.
Considering the power of Google search technology and the droves of information the company possesses, it's a compelling alternative to Siri.
Google has released a demo video showing off the new app, embedded.