The details here is that Siri seems to use some sort of authentication token when contacting the server that the iPhone 4 isn't sending, so it's rejected. We'll

The details here is that Siri seems to use some sort of authentication token when contacting the server that the iPhone 4 isn't sending, so it's rejected. We'll have to see if it's possible to work around that or share the token with a real 4S first.