At the BW2 coverage in the news section at one point it says "09:11; Defeating Unova Leaders unlocks the other regions (Kanto, Johto, Hoenn, Sinnoh)." This can easily be misinterpretted, making people believe you can actually go to Kanto, Johto, Hoenn and Sinnoh.
New Unova Pokedex page: Koffing and Weezing are listed twice, once as numbers 46 and 47, and once at the bottom of the page as having unknown dex numbers.
http://www.serebii.net/black2white2/unovadex.shtml