Yes I did.
The Nintendo DSi will come with slightly larger screens, a small camera, SD card compatibility and other features (if I remember correctly). This is all at the cost of the GBA slot, so don't go throwing out your old DS or DS Lite just yet.
Guitar Hero fans, Rumble Pak fans and Diamond/Pearl/Platinum fans should all keep their old DS (Lite), else they will be affected greatly. Personally, I'm keeping it so I can transfer all my Pokemon to Platinum when I get it instead of having to borrow my sister's pink DS :p