That said, you did let your domain expire. This is really tough to do unless you're not getting admin reminders (I think you get 3 before it expires?). If your domain is important or valauble why would you save a piddly few bucks and wait until it's near expiry? Buy multiple years or auto renew. This is not a "brilliant new scam"; registrars and 3rd parties have been doing it since we all used verisign.
Also, how do you know it was purchased by GoDaddy? How can you tell the differnce between someone else registering and parking it with them?