Such is the level of obsession that Pokémon X & Y will demand, some may consider going the download route so that it's always available without any pesky cart swapping. Even though the games aren't out until October, news has already emerged of just how much SD card space you'll need to make that happen.
This is courtesy of images of download code cards that will be available in Japan, which are common in the region; that said, we'd expect similar cards in Europe courtesy of Nintendo's eShop card distribution deal with GAME stores. According to these cards you'll need 1.7GB of space, which is around 14,000 blocks, in order to squeeze the game onto the system; this will make it one of the larger 3DS game downloads. It must be those new visuals and additional 'mon, and may necessitate some SD card upgrades as a result.
The title will also hog a little under half of the pack-in SD card with the limited edition 3DS LL (XL) bundles coming to Japan. There are two varieties coming, each with one of the games pre-installed, and Serebii has dug up images of the packaging for us to gaze upon. It's safe to say that some 3DS hardware bundles with these games should also come to the West; if not, it's a missed opportunity.
Are you considering downloading Pokémon X & Y, and if so will you need to upgrade your SD card?