Nobody has yet. We'll announce the moment they start going out. You'll have to give it a few days before they're all sent and received, so keep that in mind too!
Been looking at decred for some time, just started registering for an account yesterday, I wonder if I'll be given an invitation as well?
To everyone, airdrop registration was a 2 step process. You went to decred website and entered your email id and a link to your online presence/activity/profile. This step is over & registration is closed. If you missed this then unfortunately you can't register for airdrop anymore. In second step, you receive an email at ID you entered in first step, you just need to follow the steps/links mentioned in email. If you have not received a email, first check your spam folder for it, if it is not there please contact @_ingsoc. This step will remain open until 25th January 2016. After that testnet will be launched.
The deadline to submit an application for the airdrop was the 18th. The invitations are only for people who submitted an application and were accepted.