pokemon TCG online is a very unattractive product for me, but I could get behind another game like this, provided they give this to an actual Gamefreak team to work on and they don't just throw some generic Ken Sugimori character designs at a third party.
the game could have the cards project Pokemon holograms reused from the X and Y models, and use the X and Y Engine's overworlds, incorporating 3D far more because of improvements to the engine. the best part would be ease of access to cards by making an AR mode where if the 3DS picks up the card art for a pokemon, i tpops out the model for that pokemon/trainer/etc and then the card becomes available in a special card shop for you to purchase for a small fee of Pokedollars.
Oh, and because the 3DS has an IR port, Card Pop can return!
... speaking of which, Card Pop. Has anybody gotten to try it...? I briefly remember doing it with my 10 year old self. you'd hold your game boy color's IR port up to a friend's and if they saw each other for a few seconds, random cards would get added to one another's collections...! there was even 2 promos you can only get via it. one was a Venusaur without Energy Trans, which immediately made it garbage (it instead gets a Full heal in the form of a Poke Power, and it can't even heal itself, so... you might as well use switch!), and the other was a Mew card that has 1 psychic and 1 colorless for an attack that did whatever the **** it wanted. random damage, random statuses.
You actually got a physical copy of the Venusaur with copies of the official Nintendo Power strategy Guide.