The DS could only hold 512MB of data but now the 3DS can hold 8GB, so I expect lots of post game features such as a battle frontier and rebattling gym leaders. --- The Boondocks on Adult Swim is my favorite anime.
I don't think any 3DS game has used an 8GB cart yet. Resident Evil: Revelations uses the most memory so far which is on a 4GB card IIRC. Most Nintendo games have been either 1GB or 2GB so don't expect Game Freak to go overboard. --- Official everything of every board.
I'm thinking 4GB at most. Fire Emblem Awakening is (I think) a 2GB game and it is ~11,000 blocks. Pokedex 3D Pro is ~2500. Since this game will (probably) use all those models, just with cel-shading, it will be at least 2500 blocks, most likely a lot more because it's an actual game as compared to Pokedex 3D Pro. --- Official Zangoose of the Pokemon X board+Only member of my one-man team 3DS FC: 3609-1237-6725