The Virtual Console releases of Gold & Silver are on their way at $9.99 each, and a couple of 3DS themes are waiting for you depending on where you purchase the game:
The first 2 are available if you purchase directly on the eShop, and correspond to the game you pick. The 3rd, which scrolls to show more gym leaders on top as well as Elm, Kurt, and other characters on the bottom is a bonus for purchases made at Gamestop, Best Buy, or on Amazon. However, people are reporting that Amazon purchases are not getting the Celebi code for S/M, so be careful if you really want one!