Before the release of the iPhone 4S, Apple also implemented Siri in the beta version of iOS 5 for the iPhone 4 terminal, the company's employees having possibility to test how the new personal assistant works on the old device. The information comes from a source inside Apple who claims that the company from Cupertino considered the possibility of officially implementing the new assistant in iPhone 4, but in the end removed it from the public iOS 5 and from the version given to employees. However, until recently the company's employees played with the assistant, although the iPhone 4S was already on the market, and I think the tests were successful because port made just last week reveals that Siri works without problems with the old device.
Apple is still considering releasing Siri on the iPhone 4 and even went as far as installing a special build of iOS 5, that includes Siri, on a number of Apple employee's iPhone 4 handsets recently to test it out for a few days. Of course, the fact that Apple tested Siri on the iPhone 4 is a given. However, the fact that they're considering it after the iPhone 4S release and even letting employees use it outside of the campus as a test drive shows that there still is a chance this will become a reality. Yet, Apple has now finished the test drive and removed the feature from the employees' iPhones to minimize the chances of it getting out. We're hoping it's because they want it to be a surprise, and not because they've decided not to release it.
Although many would see in this information a tacit confirmation of the fact that Apple could implement Siri in the iPhone 4, I recommend that you return with your feet on the ground because Apple will not make such a mistake. Siri is the main thing for which people buy iPhone 4S and the implementation in iPhone 4 would immediately cancel the advantage of the new device and would drastically reduce sales. No company in the world has a management "bad" enough to make such a decision, so don't expect Siri to arrive on the iPhone 4. If it does arrive, then it means that Apple will either reduce its functionality or have other novelties prepared for the iPhone 4S in order to give it a great advantage over the old devices.
Finally, I will tell you that the Siri tests on the iPod Touch 4G were not successful because of the microphone implemented in the device, Apple preferring to close the test sessions long before those for the iPhone 4.
A second source also confirmed to us that the test went really well as far as performance is concerned. Unfortunately, the microphone of the iPod touch 4G is not as good as the one on the iPhone; this could hold Siri back from that device if it can't be overcome with software.
