I'm not so sure it's like Siri .. it's my undersatanding Siri is a voice controlled "search" assistant .. but if you watch the video here:http://linuxforums.org.uk/index.php?topic=10614.msg80224#msg80224
it sounds like the Ubuntu thingy is more of a voice "command" to the OS doodad .. that said, Ubuntu can "search" too .. so maybe you could say "search for tolkien" and it will "display" websearch returns.
So maybe it's vaguely
"Siri " but I'm guessing it's more like Dragon NaturallySpeak
ing, or IBM's old ViaVoice.