They should do what they did with DESTOROYAH; behind the credits show clips from his previous movies.
With a difference.
Have clips from EVERY movie, all previous 27 plus some from this one as well. And have every single kaiju Godzilla has ever run into, from Orga to Ookondru. Even Kong and Jet Jaguar.
Then on the DVD, they could include that in its own section where you could watch it minus credits, as "Godzilla over 5 decades" or something.