Strong rumour that the third game to Sun & Moon will be exclusive on this and will change things up a bit. It may be a little strange for fans of the games for the last 10 years where it's been on the DS and made some good leaps utilizing two screens, going back to one. There is an App on the 3DS called Pokémon Bank (lets you store up to 3000 Pokémon from any game you plug in) and through a bit of fiddling with GameBoy Advance games, the original DS / DS Lite models, and this App, it is possible even now to have your Pokémon from Ruby/Sapphire from 2003~ (FireRed/LeafGreen/Emerald a little later) in the current games. It is strongly rumoured that an updated version of Pokémon Bank will be available on the Switch, but it will act as more of a one-way system to transfer Pokémon to this next game. At the moment (well come later this month), you can send Pokémon from previous games to Sun & Moon (even including from Pokémon Red, Blue, and Yellow on the Virtual Console downloads). You can even send them back to previous games provided they do not have any newly released moves, abilities etc (or aren't a new species entirely).
I don't think this game will be announced this weekend though. They won't want to deter people from buying Sun & Moon already, so will probably wait until at least e3, if not give it its own Nintendo Direct presentation like last time. My expectation for release would be around October/November this year.
