If your asking about if GameCube games can use the WiFi connection the answer is No, All games that used the GameCube Broadband or Modem Adaptors (PSO, Homeland, Kirby Air Ride, ext) can't see the WiFi connection. So in order to play any of these online or over the network you'll need to dig out your GameCube.
It would be great if they could, but its kind of pointless. PSO is getting shut down early next year and out side MK

D all the other network games kind of sucked.
I would like to see us able to play the GBA connectivity games with the DS but I think that is unlikely too since they are designed for the GBA and we already know that the DS lacks GBA connectivity. Sadly we will be stuck with using our old GBAs and GBA/GameCube cables. No firmware can fix this since its a problem on the DS side.