The official answer is already posted on the Tesla forums:
We recently began to apply P85, 85, and 60 badges to newly produced cars in Fremont. 40 kWh cars will also receive badges once production starts. In the coming weeks, we will begin stocking these at our service centers for placement on delivered cars on request. If you have taken delivery of a Model S without a badge and would like one added, we'll be happy to apply one during your next service appointment. All you need to do is ask.