Wario Land 4 baby.....if the resolution and the size of the screen are just right I'm in. 
After all, these 'are' hand held titles....Unlike the NES amb' titles which just feel so unmagical and packed so much less of a punch when played on the 3DS. I played a few or so for a few minutes but had to stop because of the major suckage.
NES games are ment to be played on a TV, not a dinky little screen.....Besides the 3DS's Start and Select buttons are such a pain in the Don Flaminco's bunz to use.
I was playing Super Mario Bros. on the 3DS a couple of weeks ago, but it just didn't feel right......I find it stupid of Nintendo to releas NES games on a Hand held, it just seemed like pointless milkage'...but these GBA games will be the real and 'make sense' deal. 
But it'll probably be right before Christmas.