Yep. Except it won't tell you a joke when you ask it to do something.
What exactly are you trying to do with voice reco?
Edit: simple example. Pair with bluetooth to your car. Now, drive somewhere. When a text comes in, WP8 (and 7 for that matter) will prompt via bluetooth "message from X - read it or ignore" you say "read it" it does. Then it prompts "reply or I'm done" you say Reply it says say your message you say OK thanks I have just replied to your message without endangering fellow drivers" it reads that back to you and offers try again, add, or send" you say send, it sends the txt.
Siri,,, yeah Siri wouldn't get you far with that scenario. Perhaps you should learn how to use your phone?
Voice Controlled: A guide to using speech with Windows Phone 8 | Windows Phone Central