POSSIBLY! The 6th gym leader says she has a passenger plane (which sounds promising). They might come out with an event for traveling to all of the past regions. Genesect, a VERY rare Pokemon in the games, might be a part of this event. KEEP THOSE MASTER BALLS WARM, YOU MIGHT NEED THEM!
You can't.
some show up in white forest
Unova is the only region you can play through in Black and White.
There is no kanto champion. But there is sinnoh champion Cynthia at undella bay
Sadly, you cant
go on serebii.net and look at their pokedex. it will tell you all Pokemon from kanto to Iishu (Pokemon black/white)
You can't.
No you cannot find Gary in Pokemon black/white but you can find him in the kanto region.
He was seen but you cant go to where he is cause he went to sinnoh in Pokemon white and in Pokemon black kanto
Kanto is not programmed into Pokémon White.
Impossible your in the unova Region
Nowhere , you see, Eevee is not in the new one where black and white takes place. Eevee is in the Kanto region so it's not in Black and White.