Nina will allow any iOS and Android developers add voice capabilities into their app by using Nuance Communication’s Software Development Kit. Nuance is the company that powers Siri’s voice.
I am not sure how good all these apps will cork, cause SIRI is a hardware dependent app. Iphone 4S was designed to take advantage of SIRI. The noise cancellation technology is built into 4S hardware.
-SIRI doesn't work if you don't have internet connection,
-Noise cancellation technology was built into the Google Nexus One
-For the 4s the only thing they keep advertising is SIRI, a beta product. I'd be more inclined to get that device cuz of its camera, but you never hear a peep about that.