According to Enterplay's Facebook Page, there was a bit of a derp during the production of the Pre-realease sets. The exact quote is as follows:
Pre-Release Announcement - All Yellow & White Decks
Due to a production error, all players will need to play Yellow/White Manes for this event (Celestia/Rarity). Unfortunately, the incorrect Purple/Blue Manes (Luna/Rainbow Dash) were inadvertently featured on the top of Yellow/White decks - in order to have fun and play with Canterlot Nights cards at their pre-release, we are suggesting you bring a printed copy of the Celestia and Rarity cards featured here to use as proxy for your Manes for this event. We truly apologize and hope everyone has a great time over the weekend.
(Get the printed proxies of these two up above! Remember, you need both cards for both Celestia and Rarity.)
And in other news, Enterplay has released a whole bunch of resources for all of you rarin' to get your hands on Canterlot Nights this weekend. If you need help finding one, hit up the map covering both USA and Canada here!
Get everything else, card list included, below the break.
(Update: Different Celestia to print instead!)
Have some resources:
Full Card Listing, including Canterlot Nights
Full Rulebook Version 2.0
Rules Update Summary FAQ
And as a reminder, the actual official street date is now the 23rd of May.
Thanks to Mr. Offspring and everyone else for sending this stuff!