Take it with a grain of salt, BUT
All I can really say is it's about freaking time. All I can hope for now is the release of really Good GBA games that weren't just the ambassador titles.
Source: http://www.destructoid.com/natsume-confirms-that-nintendo-is-working-on-gba-vc-269811.phtml
EDIT: Thanks Auto Correct for not doing your one Fucking job and turning being into wing T_T
Once upon a time, Nintendo delivered a handful of Game Boy Advance classics (like Metroid Fusion) to the 3DS as part of the Ambassador program. The only problem is, they never really followed up on adding any GBA games after that. We've all been in some kind of limbo as to whether or not GBA support would ever really happen, but a Natsume community manager has confirmed that Nintendo is working on it.
All I can really say is it's about freaking time. All I can hope for now is the release of really Good GBA games that weren't just the ambassador titles.
Source: http://www.destructoid.com/natsume-confirms-that-nintendo-is-working-on-gba-vc-269811.phtml
EDIT: Thanks Auto Correct for not doing your one Fucking job and turning being into wing T_T