How much compatibility is there between gen VI and gen VII?

Question

Can we migrate yet? can we back trade? can items be sent from gen VI to gen VII? I don't have S&M yet so I can't test anything

Comments

As much as there is between Gen 5 and Gen 6 basically.

Answer 1

Unfortunately, PokeTransfer & PokeBank is unable to migrate Pokemon to Gen VII currently; it is said that migration to Gen VII will be available in January 2017.

No news has been announced on new compatibility updates, therefore it can only be inferred that Gen VII will be like its predecessors; Sun and Moon will probably only trade between each other and Pokemon are likely unable to be transferred to previous generations. And as per the current PokeTransfer restrictions, unfortunately, Pokemon with items are probably disallowed from migration.

Hope I helped. :)
Source and inference

Answer 2

Update

Pokémon from XY/ORAS can be sent through Pokebank to SM/USUM. There isn’t any backwards compatibility. Items cannot be transferred through Pokebank. You can only trade with other people with SM/USUM (but you can’t trade new items/Pokémon/moves from USUM to SM).
Also, as this question says “gen VII”, I’ll include LGPE transfer as well.
If you have the premium Pokebank, you can transfer from bank to home. This included gen 6 Pokémon. This is a one way transfer. You select the Pokémon you want to transfer, and a moving code will be displayed in home, which you have to type in on bank. Then you wait a minute, and your Pokémon will be in HOME. Pokémon from the Kanto region can be brought in to LGPE.