MrPop said:
So can I just borrow games from friends and install them on my DS I wonder.
NO! Don't you ruin this for us! I do not want DRM on my 3DS games!
Besides, It copies save data too and most likely transfers it back to the cartridge when you want to remove it from the list to make room for other games. We don't know how much space these games take up or how big the 3DS's internal storage is so there's no way to tell if you can hold 3 games or 10, so you might be swapping out a lot.
Meaning unless you don't care about save data, you might have to download your friends game again and again if you have your own collection of games. In which case you can't keep your save data.