Those that bought a 3DS at launch, and subsequently got stung by a drastic price cut, received 10 NES and 10 Game Boy Advance games as compensation. The NES games, and others from the system's library, have been gradually arriving in the eShop so that non-Ambassadors can join in, but Nintendo has consistently reiterated that it has "no plans" to do the same with GBA titles. If a new listing on Nintendo's Australian website is any indication, that policy may be set to change.
As spotted by fancensus.com, an official page exists for Dr. Mario on Game Boy Advance. It's interesting that this was released as part of the Classic NES Series on the handheld, and an enhanced remake was also released as part of a 2-in-1 title, Dr. Mario & Puzzle League. There's a possibility that this listing meant to show NES as the platform, so there should still be a degree of caution about this one.
Nevertheless, if this is a potential starting point for Game Boy Advance releases on the 3DS Virtual Console, which titles do you want to see the most?