I would love if that worked offline, too. Even if it is just a very limited use of voice recognition.
Like, Siri has to be online cause everything is processed on Apple's servers because there are so many things Siri could do. But if all I want is to be able to say "play <NameOfMovie/TVShow>", I would love it if that could be done offline. Even if I had to train the system myself.
Say I have 30 TV Shows in the library, I could see myself train the system the names of all of them if that meant I am able to actually start them via voice.
I was just thinking the same thing - I use XBMC on an Android TV stick now, with a wireless "airmouse" that's absolutely horrible to use, and I'd love a better option... For stuff that can easily be done with the XBMC web client, or a simple media remote it's not such a big deal, but it's not exactly a perfect solution.