The Johto Region: REVEALED and HUGE! (Kanto not shown yet...)

[Naraku_Diabolos]

Mr Khan said:

That mist looks to be replacing the old Battle Tower, just as was already said

Not just that, but the mist is covering up other areas on that map. GameFreak did the same thing when unveiling Sinnoh. There was mist on 1/4 of the whole map.