Well i think that not instantly directly hit will hurt 3DS sales, Because of the big installbase of DS, there's almost not so much to sell more than what already has been sold, so it'll not push the DS sales, And no one will go buy a Nintendo 3DS just to play a DS game, so these games like almost BW, (these 2 almost unafected DS sales worldwide basis), these games will not push any system sales.
You can argue, yes but people can buy a 3DS to play future games, those people will just wait for these future games, and then they'll bought a 3DS, it'll be very low the situation of someone buying a 3DS to play these games.
So these games will just do nothing in terms of consoles sales, well they'll do but it will be almost unsignificant. i bet for and 2~3% worldwide sales push in that time and 4~5% of 3DS sales push.