UPDATE: Unfortunately, like a number of rumors, it seems this one has been squashed. From the Nintendo Australia website:
Nintendo Australia would like to confirm the recent update to the website highlighting Game Boy Advance titles are available on Nintendo eShop was posted in error. Nintendo Australia can confirm there are no current plans for Game Boy Advance games to be released on Virtual Console for Nintendo 3DS. We would also like to confirm Dr. Mario is available as a Game Boy title on Virtual Console via Nintendo eShop. We would like to apologise for any confusion this has caused.
So, as guessed, it was a mistake in placement. The celebration of Game Boy Advance games coming to the Virtual Console will have to be put on hold.
However, it must be said that you would expect Nintendo to eventually release GBA games at some point. Right?
Original Rumor Below:
Game Boy Advance games may be coming to a 3DS Virtual Console near you. Nintendo Australia has created a spot on its website for GBA games, possibly signaling the beginning of Nintendo selling GBA games on VC. The first game listed is Dr. Mario from the GBA’s Classic NES Series.
So far, only those that bought the Nintendo 3DS before the price drop are able to play Game Boy Advance games on their 3DS as part of the Ambassador program. Nintendo of America has slowly released some of the free NES games, but not those that were on the GBA. If this development pans out, it could mean the beginning of the sale of GBA games (and not just those that were offered in the Ambassador program).
However, there is a bit of caution before we celebrate just yet. Dr. Mario is currently listed at $4.50(AU). That is roughly the price of a regular Game Boy game and $1.50 to $2.50 less than Game Boy Color games from the VC in Australia. Given that Dr. Mario was released on multiple consoles, it could just be a mistake in placement. Until we get confirmation, let’s temper the excitement of Nintendo finally releasing Game Boy Advance titles for the Virtual Console.
Source (http://www NULL.nintendo NULL.com NULL.au/index NULL.php?action=catalogue&pageID=47§ionID=3&prodcat_id=154)