Yes, they make cases, screens, styluses, and many others.
Mad Catz makes a carrying case for the PSP as well as a car charger, which is great for road trips.
Nothing specifically. But any accessories that you use hands for, you can use.
Yes. These products are available through the Nintendo website and distinguished by an official seal.
Pelican doesn't make any accessories for the PSP. However Sony has a wide line.
Yes the Nintendo DS and the Wii work together on a few game titles.You can do without any additiona accessories.
No. For example, you can't call Nintendo and ask them to make you a Game Boy Advance. They won't.
No, only for Nintendo consoles.
There are no first-party Nintendo accessories for customizing the appearance of the console, however, a number of authorized third party manufacturers offer console skins, controller covers and even customized stands for the Wii which can be used to change its appearance. These accessories are available for purchase from most major retailers including Best Buy and Toys R Us.
No, the nintendo just simply does not have the space or capability to make such a huge game.
Purr Pals, for the Nintendo DS
Unfortunately, there are no legal means of playing DVDs on any Nintendo consoles at the present time. Nintendo chose to exclude this capability to keep licensing costs down and focus on gaming rather than movie playback. It is theoretically possible to modify a Wii to play DVDs, however, this modification invalidates the warranty.
The 3DS does not have a slot-2, it cannot use any accessories developed for it such as the Guitar Hero addon or the DS lite rumble pack. Those are only compatible with the original DS and DS lite.