A bit more information has popped up for the MLP Trading Card Game revealed earlier on the MLP Twitter feed. These two surprisingly dark images are the official announcement ads for it. That is definitely a lot less pink than I am used to. You can expect to see booster packs and starter decks, similar to other collectable card games once it does release, and those going to gen-con will be able to try out playable demos. Fingers crossed that this turns out awesome! Hasbro does technically have a hand in Wizards of the Coast, so hopefully that will help out a bit!
Update: Head over here for loads more information on it, as well as a prototype card image.