Will there ever be something like Apple's Siri available for all platforms?

Siri was originally to be released for various platforms (iOS, Android, PC, and maybe even Linux and others at some point), but Apple bought the technology and is making it available only on Apple products :-(

I’d love to have something like Siri, but I’m not a big fan of Apple products.

Now that the technology exists, how soon will competitive products come to other platforms?

And will they have the same “irreverent personality” that makes Siri talked about and desired by so many people?