I haven't been online with my 3ds XL. I bought it to use it with the Gateway card. I have another 3ds. With that one I can access the shop.You'll have to create a new NNID anyway unless your doing a system transfer
What I want to know is if Nintendo can see I am using 3ds with a Gateway and Emunand to access the shop. And will they close my Nintendo ID so that I cannot access the shop from my other 3ds (or even get into problems with my DS lite, DSi, Wii or WiiU).
In that case I make a new account.