elementary! to get more people to buy it like crazy at THEIR store.
Frankly All that intec stuff they're offering is generally useless. A Car adapter? feh, Headphones? Use your GBA headphones or NORMAL ones because it has a real jack now, Screen protectors? maybe for the touch screen it might be useful but other wise it's not like you cant buy those separatly.
Personally all I'd need is the system and a game to play, and thouse I'll probably snag from the local game shop when they get them in for 5 bucks less than the chain stores because I'm in no big rush.