It's sad, but twitter's not transferring it back in a week's time gives me more confidence in twitter, not less. There isn't any evidence of the stealing of the domain names and the extortion available besides OP's copies of the email messages and information that GoDaddy won't provide. With the value twitter ID has, twitter shouldn't do anything without clear evidence.
He might have been able to get it back if it was his trademark or even name that he lost and not some witty username.
I value any company's committment to security however there are ways that Twitter can prove who the owner of the account was, if they really wanted to.
Let's see if this story hits real news headlines and affects Twitters stock before closing bell tomorrow and action will happen.
I was thinking how witty that would be if THIS was the actually hacker, and he was using us to create a shitstorm in order to rush Twitter into giving him the account. I'm sure there is sufficient data to support that he was the original owner though.
He might have been able to get it back if it was his trademark or even name that he lost and not some witty username.