No. They are not the same. The players in B/W are traveling with Zekrom or Reshiram around Unova and the other one (Zekrom or Reshiram) are traveling with N. You cannot see them, unless talking to the player's mom after you beat W2/B2.
Black and White 2 MAY be the sequel to it however in three years time. A gap like this can have numerous events counting, and so they might have let Unova or they are traveling with the a lengendary Pokèmon (see above)
Still, they are not the same. The sprites aren't the same and the cities and town have changed, along with more building too.
Edit: Prior to the comment above:
Thanks Your Worst Nightmare (credit for the names go to him)
Source: Wikipedia for quick search and Serebii