Since the launch of iPhone 4S, it was believed that iOS hackers would come with a Siri port for other iDevices. At first, they extracted all those files which were available in iPhone 4S, made it possible to port the Graphical User Interface. Another challenge was to spoof the Apple servers which was not an easy task. @stroughtonsmith and @chpwn finally turned it into reality.¬†
To claim their hack, they demonstrated a fully functional Siri in a video on iPod touch 4G. Now, the next big question was when it would be released for people to try? Of course, we would have been waited for this moment eagerly. Unfortunately, @chpwn has explained the reason why he wouldn’t be able to release the hack so soon. The first reason is the distribution of content which was never their own.
@chpwn said on his blog that he can’t distribute something which belongs to Apple including¬†files, images, and code. However, the person who owns an iPhone 4S can extract those files and use it whenever he wants. Otherwise, it is purely illegal and violation of rights by distributing them through any modes of sharing. Another reason is the encrypted files in the iPhone 4S firmware which can’t be decrypted at the moment.
Due to the fact that iPhone 4S firmware can be downloaded by anyone in the world, this process is legal and makes sense right now. Till the time, @chpwn and others find a way to decrypt those files, we need to wait. The last, partial reason is the non-availbility of iPhone 4S JailBreak to get the desired information. And he is not aware when it would be released for all. These are some of the reasons due to which iPhone 4S siri port is actually not released right now.
But yes, once all the above mentioned problems are solved, we would get a working Siri port for devices other than iPhone 4S. @chpwn has also cleared one of the point that Siri port has not yet tested for iPhone 3GS, iPod touch 3G or an iPad running on iOS 5. Though it is expected that it would work on all these devices pretty well. Till then all you can do is to wait.
If you want to read the complete explanation, check it on official @chpwn blog