I remember watching E3 and seeing the cradle and wondering why exactly we were going to be charging with a cradle. I thought at the time that the cradle would be the only way to charge the 3DS. But upon getting my 3DS I realized I could plug it into the wall just like I did with my DSi. The cradle was just an add on accessory to the plug.
So again I was thinking where is the point in the cradle. I then picked the console up with the cradle and realized it was still playable. I then looked at the input and thought to myself couldn't other devices be attached here. Right aways I thought that MadCatz could release a back up battery to extend the consoles battery life.
Then it hit me, Nintendo must have already thought of this. Infact I can't see much of a reason for the cradle if not for a future accessory. The fact is a battery accessory released maybe in line with NGP would give Nintendo's 3DS a longer battery life then the NGP (Most likely). Also another thing confirming it in my mind is the fact that the current internal battery could be much more powerful, 3 hours battery life (What I get) is not enough to satisfy most gamers.
So Nintendo could release a battery pack for say 60$ that offers an aditional 5 hours. Blamo they can sell it for a profit and make even more money. And if Nintendo doesn't what are the chances third parties won't?
"In God We Trust - In Games We Play " - Joel Reimer