No. At least not yet.
I don’t know the technical background behind Siri. But if they would make a very slight change to Siri, it could be a hundred times better:
If Siri would already listen to the user, while she’s talking (with all her very long breaks between sentences), it would feel more like a fluid conversation. It would make her more human and it would speed up the interaction.
I mean. Even the T-Com Hotline is able to listen while talking to you.