Currently, Siri Supports English, French, German and Japanese. Support for Japanese was announced recently . Apple has promised that Siri will support Italian, Chinese, Korean and Spanish languages later this year.
If you have an iOS device that is capable of supporting Siri (iPhone 4S) and have an Indian accent then you know it’s not easy to make her understand what you are trying to say in first go.
Then comes Kunal Kaul who claims (and shows on youtube) Siri speaking in Hindi and Arabic Language. Kunal claims that he used Spire and reconfigured it with the Google API to work speak in Hindi. Spire is a Siri Clone for non iPhone 4S devices built by the jailbreak community. So probably It is Spire and Not Siri speaking in Hindi.
One thing is for sure it looks cool and he’s done a pretty good job.