In order to handle all that extra functionality, Nintendo has decided to increase the RAM found inside the new Nintendo DSi compared to the older Nintendo DS Lite.
As you recall, when the Opera web browser launched for the DS it came with a RAM-boosting pack that fit in the GBA slot. Without this pack, the browser wouldn’t work. Seeing how the DSi lacks a GBA slot, something had to be done.
The extra RAM will certainly come in handy when you consider the integrated DSiWare Shop, music player, and dual cameras. It won’t be long before developers come up with some nifty uses for that extra memory.