Loads of people collected all sets of the eggs, so I doubt that they would be giving out VIP for those people because the server would loose money. Some other prizes could also include: your name in murder, gadgets and/or pets.So what im thinking is that the $20 code would have been given when all shiny eggs were collected.
Please stop double posting, you can use the edit button to add extra things to your previous message. Also, we'll find out the prizes soon.However i think it is a bit deceptive how they say : People who collect a full set of shiny eggs will be given something über special!
Then the prize is ... Nothing!!!