a 3DS successor seems extremely unecessary when the Switch is debatably heavily a handheld. Newflash: I'm sure you'll be able to get a slim case to carry your Switch in, maybe not in your pocket (maybe?) but we'll see
I honestly don't think the DS/3DS design is that inuitive, I don't find two screens particularly helpful. The only games which it particularly seems useful to me is the ones in which a map is involved (racing or an RPG with a world map). Otherwise it sort of annoys me to have two small screens. I think I'll prefer the bigger Switch screen.
I like the 3DS but don't really understand why it would help Nintendo to have a successor. all of the big N handheld fans are going to buy the Switch most likely as it does everything you'd expect from a handheld system and is far and large the most powerful dedicated handheld to date
maybe in like 5 years they'll release another dual screen handheld for you doe
