When you do the system transfer from your original 3DS over to the new XL, does it copy EVERYTHING, including what is on the memory card? Or once the transfer is done, do you take the memory card out of the 3DS and put it in to the XL?
Also, it wipes the 3DS I am guessing? It would be nice to have the same content on both, but I am assuming it will wipe the 3DS clean?
If you follow the transfer process, when is done it will wipe the original source. Anything that you downloaded for DS titles is most likely going to have to re-download (no charge); all 3DS titles are transferred flawlessly. If you have pictures, you may want to back those of first; those won't get transferred.