@hoss3000: Dragon's Crown on the PS3 does NOT come with the Vita copy. You must buy them separately.
Depends on how you want to play the game. The PS3 version has local multiplayer (You can play with up to 4 people on the same TV) so if you have friends over often the PS3 version may be something to consider. However, if you're like me and you can only sneak in gaming during short moments throughout your day, Vita copy for sure.
You could also just buy both copies. I remember seeing at E3 that you'll be able to transfer your save file from one platform to the other. Personally I'd love to get both, but since I have two other pre-orders slated for August, I'm going to hold off and get the Vita version first.
I wish Atlus would have considered making a discounted version that contained both PS3 and Vita copies in one package. The could have saved some money by just including a code and making the Vita version downloadable. We shouldn't have to pay the full retail price twice to play on both platforms.