But the concept that they had in mind isn't very good, but there is actually a very good idea that BLAZE didn't realise
I don't really see what is so hard about putting DS games into the DS, because using the Game Selector for normal game cartridges isn't much more efficient. But when you think about that with flashcards (which I don't think they had in mind), it has heaps of potential! As zeromac said, you can hold movies on one flashcard, homebrew on another, etc. Well spotted finding this accessory
All it does is connect the pins on the flashcart with those in Slot 1, and use a switch to select which set of pins are connected at one time. From a technical standpoint I see no reason why it shouldn't.
I was actually excited to see this thing...then I noticed you have to physically switch a button to change which game is played. What they should have done is given the device it's own internal rom, allowing you to choose which game you want to play straight from the DSi.
Yeah, it's interesting from a purely technical standpoint. It might make your console too bulky although. (I have tiny hands - I can wear kids magic gloves and get away with it.) I'm all for it, but I have two other games in rotation along with my flashcart - Pokemon Diamond, Animal Crossing - this would make it a lot easier to have them on hand.