So is this going to be a cartridge which will be purchased?
Yes. THe big thing that excites me about this is that I will be able to WiFi game at hotles when I travel. Pretty much all hotels require you to accept a ToS before you can browse and get your MAC registered. Without web browsing you can't play your DS over that network. However, once the Opera browser comes out, you hook up, get that MAC in there and then popo in a game and away you go.